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1 : : /* Scalar evolution detector.
2 : : Copyright (C) 2003-2024 Free Software Foundation, Inc.
3 : : Contributed by Sebastian Pop <s.pop@laposte.net>
4 : :
5 : : This file is part of GCC.
6 : :
7 : : GCC is free software; you can redistribute it and/or modify it under
8 : : the terms of the GNU General Public License as published by the Free
9 : : Software Foundation; either version 3, or (at your option) any later
10 : : version.
11 : :
12 : : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 : : WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 : : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 : : for more details.
16 : :
17 : : You should have received a copy of the GNU General Public License
18 : : along with GCC; see the file COPYING3. If not see
19 : : <http://www.gnu.org/licenses/>. */
20 : :
21 : : /*
22 : : Description:
23 : :
24 : : This pass analyzes the evolution of scalar variables in loop
25 : : structures. The algorithm is based on the SSA representation,
26 : : and on the loop hierarchy tree. This algorithm is not based on
27 : : the notion of versions of a variable, as it was the case for the
28 : : previous implementations of the scalar evolution algorithm, but
29 : : it assumes that each defined name is unique.
30 : :
31 : : The notation used in this file is called "chains of recurrences",
32 : : and has been proposed by Eugene Zima, Robert Van Engelen, and
33 : : others for describing induction variables in programs. For example
34 : : "b -> {0, +, 2}_1" means that the scalar variable "b" is equal to 0
35 : : when entering in the loop_1 and has a step 2 in this loop, in other
36 : : words "for (b = 0; b < N; b+=2);". Note that the coefficients of
37 : : this chain of recurrence (or chrec [shrek]) can contain the name of
38 : : other variables, in which case they are called parametric chrecs.
39 : : For example, "b -> {a, +, 2}_1" means that the initial value of "b"
40 : : is the value of "a". In most of the cases these parametric chrecs
41 : : are fully instantiated before their use because symbolic names can
42 : : hide some difficult cases such as self-references described later
43 : : (see the Fibonacci example).
44 : :
45 : : A short sketch of the algorithm is:
46 : :
47 : : Given a scalar variable to be analyzed, follow the SSA edge to
48 : : its definition:
49 : :
50 : : - When the definition is a GIMPLE_ASSIGN: if the right hand side
51 : : (RHS) of the definition cannot be statically analyzed, the answer
52 : : of the analyzer is: "don't know".
53 : : Otherwise, for all the variables that are not yet analyzed in the
54 : : RHS, try to determine their evolution, and finally try to
55 : : evaluate the operation of the RHS that gives the evolution
56 : : function of the analyzed variable.
57 : :
58 : : - When the definition is a condition-phi-node: determine the
59 : : evolution function for all the branches of the phi node, and
60 : : finally merge these evolutions (see chrec_merge).
61 : :
62 : : - When the definition is a loop-phi-node: determine its initial
63 : : condition, that is the SSA edge defined in an outer loop, and
64 : : keep it symbolic. Then determine the SSA edges that are defined
65 : : in the body of the loop. Follow the inner edges until ending on
66 : : another loop-phi-node of the same analyzed loop. If the reached
67 : : loop-phi-node is not the starting loop-phi-node, then we keep
68 : : this definition under a symbolic form. If the reached
69 : : loop-phi-node is the same as the starting one, then we compute a
70 : : symbolic stride on the return path. The result is then the
71 : : symbolic chrec {initial_condition, +, symbolic_stride}_loop.
72 : :
73 : : Examples:
74 : :
75 : : Example 1: Illustration of the basic algorithm.
76 : :
77 : : | a = 3
78 : : | loop_1
79 : : | b = phi (a, c)
80 : : | c = b + 1
81 : : | if (c > 10) exit_loop
82 : : | endloop
83 : :
84 : : Suppose that we want to know the number of iterations of the
85 : : loop_1. The exit_loop is controlled by a COND_EXPR (c > 10). We
86 : : ask the scalar evolution analyzer two questions: what's the
87 : : scalar evolution (scev) of "c", and what's the scev of "10". For
88 : : "10" the answer is "10" since it is a scalar constant. For the
89 : : scalar variable "c", it follows the SSA edge to its definition,
90 : : "c = b + 1", and then asks again what's the scev of "b".
91 : : Following the SSA edge, we end on a loop-phi-node "b = phi (a,
92 : : c)", where the initial condition is "a", and the inner loop edge
93 : : is "c". The initial condition is kept under a symbolic form (it
94 : : may be the case that the copy constant propagation has done its
95 : : work and we end with the constant "3" as one of the edges of the
96 : : loop-phi-node). The update edge is followed to the end of the
97 : : loop, and until reaching again the starting loop-phi-node: b -> c
98 : : -> b. At this point we have drawn a path from "b" to "b" from
99 : : which we compute the stride in the loop: in this example it is
100 : : "+1". The resulting scev for "b" is "b -> {a, +, 1}_1". Now
101 : : that the scev for "b" is known, it is possible to compute the
102 : : scev for "c", that is "c -> {a + 1, +, 1}_1". In order to
103 : : determine the number of iterations in the loop_1, we have to
104 : : instantiate_parameters (loop_1, {a + 1, +, 1}_1), that gives after some
105 : : more analysis the scev {4, +, 1}_1, or in other words, this is
106 : : the function "f (x) = x + 4", where x is the iteration count of
107 : : the loop_1. Now we have to solve the inequality "x + 4 > 10",
108 : : and take the smallest iteration number for which the loop is
109 : : exited: x = 7. This loop runs from x = 0 to x = 7, and in total
110 : : there are 8 iterations. In terms of loop normalization, we have
111 : : created a variable that is implicitly defined, "x" or just "_1",
112 : : and all the other analyzed scalars of the loop are defined in
113 : : function of this variable:
114 : :
115 : : a -> 3
116 : : b -> {3, +, 1}_1
117 : : c -> {4, +, 1}_1
118 : :
119 : : or in terms of a C program:
120 : :
121 : : | a = 3
122 : : | for (x = 0; x <= 7; x++)
123 : : | {
124 : : | b = x + 3
125 : : | c = x + 4
126 : : | }
127 : :
128 : : Example 2a: Illustration of the algorithm on nested loops.
129 : :
130 : : | loop_1
131 : : | a = phi (1, b)
132 : : | c = a + 2
133 : : | loop_2 10 times
134 : : | b = phi (c, d)
135 : : | d = b + 3
136 : : | endloop
137 : : | endloop
138 : :
139 : : For analyzing the scalar evolution of "a", the algorithm follows
140 : : the SSA edge into the loop's body: "a -> b". "b" is an inner
141 : : loop-phi-node, and its analysis as in Example 1, gives:
142 : :
143 : : b -> {c, +, 3}_2
144 : : d -> {c + 3, +, 3}_2
145 : :
146 : : Following the SSA edge for the initial condition, we end on "c = a
147 : : + 2", and then on the starting loop-phi-node "a". From this point,
148 : : the loop stride is computed: back on "c = a + 2" we get a "+2" in
149 : : the loop_1, then on the loop-phi-node "b" we compute the overall
150 : : effect of the inner loop that is "b = c + 30", and we get a "+30"
151 : : in the loop_1. That means that the overall stride in loop_1 is
152 : : equal to "+32", and the result is:
153 : :
154 : : a -> {1, +, 32}_1
155 : : c -> {3, +, 32}_1
156 : :
157 : : Example 2b: Multivariate chains of recurrences.
158 : :
159 : : | loop_1
160 : : | k = phi (0, k + 1)
161 : : | loop_2 4 times
162 : : | j = phi (0, j + 1)
163 : : | loop_3 4 times
164 : : | i = phi (0, i + 1)
165 : : | A[j + k] = ...
166 : : | endloop
167 : : | endloop
168 : : | endloop
169 : :
170 : : Analyzing the access function of array A with
171 : : instantiate_parameters (loop_1, "j + k"), we obtain the
172 : : instantiation and the analysis of the scalar variables "j" and "k"
173 : : in loop_1. This leads to the scalar evolution {4, +, 1}_1: the end
174 : : value of loop_2 for "j" is 4, and the evolution of "k" in loop_1 is
175 : : {0, +, 1}_1. To obtain the evolution function in loop_3 and
176 : : instantiate the scalar variables up to loop_1, one has to use:
177 : : instantiate_scev (block_before_loop (loop_1), loop_3, "j + k").
178 : : The result of this call is {{0, +, 1}_1, +, 1}_2.
179 : :
180 : : Example 3: Higher degree polynomials.
181 : :
182 : : | loop_1
183 : : | a = phi (2, b)
184 : : | c = phi (5, d)
185 : : | b = a + 1
186 : : | d = c + a
187 : : | endloop
188 : :
189 : : a -> {2, +, 1}_1
190 : : b -> {3, +, 1}_1
191 : : c -> {5, +, a}_1
192 : : d -> {5 + a, +, a}_1
193 : :
194 : : instantiate_parameters (loop_1, {5, +, a}_1) -> {5, +, 2, +, 1}_1
195 : : instantiate_parameters (loop_1, {5 + a, +, a}_1) -> {7, +, 3, +, 1}_1
196 : :
197 : : Example 4: Lucas, Fibonacci, or mixers in general.
198 : :
199 : : | loop_1
200 : : | a = phi (1, b)
201 : : | c = phi (3, d)
202 : : | b = c
203 : : | d = c + a
204 : : | endloop
205 : :
206 : : a -> (1, c)_1
207 : : c -> {3, +, a}_1
208 : :
209 : : The syntax "(1, c)_1" stands for a PEELED_CHREC that has the
210 : : following semantics: during the first iteration of the loop_1, the
211 : : variable contains the value 1, and then it contains the value "c".
212 : : Note that this syntax is close to the syntax of the loop-phi-node:
213 : : "a -> (1, c)_1" vs. "a = phi (1, c)".
214 : :
215 : : The symbolic chrec representation contains all the semantics of the
216 : : original code. What is more difficult is to use this information.
217 : :
218 : : Example 5: Flip-flops, or exchangers.
219 : :
220 : : | loop_1
221 : : | a = phi (1, b)
222 : : | c = phi (3, d)
223 : : | b = c
224 : : | d = a
225 : : | endloop
226 : :
227 : : a -> (1, c)_1
228 : : c -> (3, a)_1
229 : :
230 : : Based on these symbolic chrecs, it is possible to refine this
231 : : information into the more precise PERIODIC_CHRECs:
232 : :
233 : : a -> |1, 3|_1
234 : : c -> |3, 1|_1
235 : :
236 : : This transformation is not yet implemented.
237 : :
238 : : Further readings:
239 : :
240 : : You can find a more detailed description of the algorithm in:
241 : : http://icps.u-strasbg.fr/~pop/DEA_03_Pop.pdf
242 : : http://icps.u-strasbg.fr/~pop/DEA_03_Pop.ps.gz. But note that
243 : : this is a preliminary report and some of the details of the
244 : : algorithm have changed. I'm working on a research report that
245 : : updates the description of the algorithms to reflect the design
246 : : choices used in this implementation.
247 : :
248 : : A set of slides show a high level overview of the algorithm and run
249 : : an example through the scalar evolution analyzer:
250 : : http://cri.ensmp.fr/~pop/gcc/mar04/slides.pdf
251 : :
252 : : The slides that I have presented at the GCC Summit'04 are available
253 : : at: http://cri.ensmp.fr/~pop/gcc/20040604/gccsummit-lno-spop.pdf
254 : : */
255 : :
256 : : #include "config.h"
257 : : #include "system.h"
258 : : #include "coretypes.h"
259 : : #include "backend.h"
260 : : #include "target.h"
261 : : #include "rtl.h"
262 : : #include "optabs-query.h"
263 : : #include "tree.h"
264 : : #include "gimple.h"
265 : : #include "ssa.h"
266 : : #include "gimple-pretty-print.h"
267 : : #include "fold-const.h"
268 : : #include "gimplify.h"
269 : : #include "gimple-iterator.h"
270 : : #include "gimplify-me.h"
271 : : #include "tree-cfg.h"
272 : : #include "tree-ssa-loop-ivopts.h"
273 : : #include "tree-ssa-loop-manip.h"
274 : : #include "tree-ssa-loop-niter.h"
275 : : #include "tree-ssa-loop.h"
276 : : #include "tree-ssa.h"
277 : : #include "cfgloop.h"
278 : : #include "tree-chrec.h"
279 : : #include "tree-affine.h"
280 : : #include "tree-scalar-evolution.h"
281 : : #include "dumpfile.h"
282 : : #include "tree-ssa-propagate.h"
283 : : #include "gimple-fold.h"
284 : : #include "tree-into-ssa.h"
285 : : #include "builtins.h"
286 : : #include "case-cfn-macros.h"
287 : :
288 : : static tree analyze_scalar_evolution_1 (class loop *, tree);
289 : : static tree analyze_scalar_evolution_for_address_of (class loop *loop,
290 : : tree var);
291 : :
292 : : /* The cached information about an SSA name with version NAME_VERSION,
293 : : claiming that below basic block with index INSTANTIATED_BELOW, the
294 : : value of the SSA name can be expressed as CHREC. */
295 : :
296 : : struct GTY((for_user)) scev_info_str {
297 : : unsigned int name_version;
298 : : int instantiated_below;
299 : : tree chrec;
300 : : };
301 : :
302 : : /* Counters for the scev database. */
303 : : static unsigned nb_set_scev = 0;
304 : : static unsigned nb_get_scev = 0;
305 : :
306 : : struct scev_info_hasher : ggc_ptr_hash<scev_info_str>
307 : : {
308 : : static hashval_t hash (scev_info_str *i);
309 : : static bool equal (const scev_info_str *a, const scev_info_str *b);
310 : : };
311 : :
312 : : static GTY (()) hash_table<scev_info_hasher> *scalar_evolution_info;
313 : :
314 : :
315 : : /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */
316 : :
317 : : static inline struct scev_info_str *
318 : 47229297 : new_scev_info_str (basic_block instantiated_below, tree var)
319 : : {
320 : 47229297 : struct scev_info_str *res;
321 : :
322 : 47229297 : res = ggc_alloc<scev_info_str> ();
323 : 47229297 : res->name_version = SSA_NAME_VERSION (var);
324 : 47229297 : res->chrec = chrec_not_analyzed_yet;
325 : 47229297 : res->instantiated_below = instantiated_below->index;
326 : :
327 : 47229297 : return res;
328 : : }
329 : :
330 : : /* Computes a hash function for database element ELT. */
331 : :
332 : : hashval_t
333 : 966877499 : scev_info_hasher::hash (scev_info_str *elt)
334 : : {
335 : 966877499 : return elt->name_version ^ elt->instantiated_below;
336 : : }
337 : :
338 : : /* Compares database elements E1 and E2. */
339 : :
340 : : bool
341 : 959690603 : scev_info_hasher::equal (const scev_info_str *elt1, const scev_info_str *elt2)
342 : : {
343 : 959690603 : return (elt1->name_version == elt2->name_version
344 : 959690603 : && elt1->instantiated_below == elt2->instantiated_below);
345 : : }
346 : :
347 : : /* Get the scalar evolution of VAR for INSTANTIATED_BELOW basic block.
348 : : A first query on VAR returns chrec_not_analyzed_yet. */
349 : :
350 : : static tree *
351 : 185808002 : find_var_scev_info (basic_block instantiated_below, tree var)
352 : : {
353 : 185808002 : struct scev_info_str *res;
354 : 185808002 : struct scev_info_str tmp;
355 : :
356 : 185808002 : tmp.name_version = SSA_NAME_VERSION (var);
357 : 185808002 : tmp.instantiated_below = instantiated_below->index;
358 : 185808002 : scev_info_str **slot = scalar_evolution_info->find_slot (&tmp, INSERT);
359 : :
360 : 185808002 : if (!*slot)
361 : 47229297 : *slot = new_scev_info_str (instantiated_below, var);
362 : 185808002 : res = *slot;
363 : :
364 : 185808002 : return &res->chrec;
365 : : }
366 : :
367 : :
368 : : /* Hashtable helpers for a temporary hash-table used when
369 : : analyzing a scalar evolution, instantiating a CHREC or
370 : : resolving mixers. */
371 : :
372 : : class instantiate_cache_type
373 : : {
374 : : public:
375 : : htab_t map;
376 : : vec<scev_info_str> entries;
377 : :
378 : 117700736 : instantiate_cache_type () : map (NULL), entries (vNULL) {}
379 : : ~instantiate_cache_type ();
380 : 113320720 : tree get (unsigned slot) { return entries[slot].chrec; }
381 : 88046706 : void set (unsigned slot, tree chrec) { entries[slot].chrec = chrec; }
382 : : };
383 : :
384 : 117700736 : instantiate_cache_type::~instantiate_cache_type ()
385 : : {
386 : 117700736 : if (map != NULL)
387 : : {
388 : 26159910 : htab_delete (map);
389 : 26159910 : entries.release ();
390 : : }
391 : 117700736 : }
392 : :
393 : : /* Cache to avoid infinite recursion when instantiating an SSA name.
394 : : Live during the outermost analyze_scalar_evolution, instantiate_scev
395 : : or resolve_mixers call. */
396 : : static instantiate_cache_type *global_cache;
397 : :
398 : :
399 : : /* Return true when PHI is a loop-phi-node. */
400 : :
401 : : static bool
402 : 23421628 : loop_phi_node_p (gimple *phi)
403 : : {
404 : : /* The implementation of this function is based on the following
405 : : property: "all the loop-phi-nodes of a loop are contained in the
406 : : loop's header basic block". */
407 : :
408 : 0 : return loop_containing_stmt (phi)->header == gimple_bb (phi);
409 : : }
410 : :
411 : : /* Compute the scalar evolution for EVOLUTION_FN after crossing LOOP.
412 : : In general, in the case of multivariate evolutions we want to get
413 : : the evolution in different loops. LOOP specifies the level for
414 : : which to get the evolution.
415 : :
416 : : Example:
417 : :
418 : : | for (j = 0; j < 100; j++)
419 : : | {
420 : : | for (k = 0; k < 100; k++)
421 : : | {
422 : : | i = k + j; - Here the value of i is a function of j, k.
423 : : | }
424 : : | ... = i - Here the value of i is a function of j.
425 : : | }
426 : : | ... = i - Here the value of i is a scalar.
427 : :
428 : : Example:
429 : :
430 : : | i_0 = ...
431 : : | loop_1 10 times
432 : : | i_1 = phi (i_0, i_2)
433 : : | i_2 = i_1 + 2
434 : : | endloop
435 : :
436 : : This loop has the same effect as:
437 : : LOOP_1 has the same effect as:
438 : :
439 : : | i_1 = i_0 + 20
440 : :
441 : : The overall effect of the loop, "i_0 + 20" in the previous example,
442 : : is obtained by passing in the parameters: LOOP = 1,
443 : : EVOLUTION_FN = {i_0, +, 2}_1.
444 : : */
445 : :
446 : : tree
447 : 5438479 : compute_overall_effect_of_inner_loop (class loop *loop, tree evolution_fn)
448 : : {
449 : 6246442 : bool val = false;
450 : :
451 : 6246442 : if (evolution_fn == chrec_dont_know)
452 : : return chrec_dont_know;
453 : :
454 : 6136860 : else if (TREE_CODE (evolution_fn) == POLYNOMIAL_CHREC)
455 : : {
456 : 2169020 : class loop *inner_loop = get_chrec_loop (evolution_fn);
457 : :
458 : 2169020 : if (inner_loop == loop
459 : 2169020 : || flow_loop_nested_p (loop, inner_loop))
460 : : {
461 : 2169020 : tree nb_iter = number_of_latch_executions (inner_loop);
462 : :
463 : 2169020 : if (nb_iter == chrec_dont_know)
464 : : return chrec_dont_know;
465 : : else
466 : : {
467 : 807963 : tree res;
468 : :
469 : : /* evolution_fn is the evolution function in LOOP. Get
470 : : its value in the nb_iter-th iteration. */
471 : 807963 : res = chrec_apply (inner_loop->num, evolution_fn, nb_iter);
472 : :
473 : 807963 : if (chrec_contains_symbols_defined_in_loop (res, loop->num))
474 : 55799 : res = instantiate_parameters (loop, res);
475 : :
476 : : /* Continue the computation until ending on a parent of LOOP. */
477 : 807963 : return compute_overall_effect_of_inner_loop (loop, res);
478 : : }
479 : : }
480 : : else
481 : : return evolution_fn;
482 : : }
483 : :
484 : : /* If the evolution function is an invariant, there is nothing to do. */
485 : 3967840 : else if (no_evolution_in_loop_p (evolution_fn, loop->num, &val) && val)
486 : : return evolution_fn;
487 : :
488 : : else
489 : 3256739 : return chrec_dont_know;
490 : : }
491 : :
492 : : /* Associate CHREC to SCALAR. */
493 : :
494 : : static void
495 : 45009413 : set_scalar_evolution (basic_block instantiated_below, tree scalar, tree chrec)
496 : : {
497 : 45009413 : tree *scalar_info;
498 : :
499 : 45009413 : if (TREE_CODE (scalar) != SSA_NAME)
500 : : return;
501 : :
502 : 45009413 : scalar_info = find_var_scev_info (instantiated_below, scalar);
503 : :
504 : 45009413 : if (dump_file)
505 : : {
506 : 69944 : if (dump_flags & TDF_SCEV)
507 : : {
508 : 8 : fprintf (dump_file, "(set_scalar_evolution \n");
509 : 8 : fprintf (dump_file, " instantiated_below = %d \n",
510 : : instantiated_below->index);
511 : 8 : fprintf (dump_file, " (scalar = ");
512 : 8 : print_generic_expr (dump_file, scalar);
513 : 8 : fprintf (dump_file, ")\n (scalar_evolution = ");
514 : 8 : print_generic_expr (dump_file, chrec);
515 : 8 : fprintf (dump_file, "))\n");
516 : : }
517 : 69944 : if (dump_flags & TDF_STATS)
518 : 7145 : nb_set_scev++;
519 : : }
520 : :
521 : 45009413 : *scalar_info = chrec;
522 : : }
523 : :
524 : : /* Retrieve the chrec associated to SCALAR instantiated below
525 : : INSTANTIATED_BELOW block. */
526 : :
527 : : static tree
528 : 175535621 : get_scalar_evolution (basic_block instantiated_below, tree scalar)
529 : : {
530 : 175535621 : tree res;
531 : :
532 : 175535621 : if (dump_file)
533 : : {
534 : 591232 : if (dump_flags & TDF_SCEV)
535 : : {
536 : 30 : fprintf (dump_file, "(get_scalar_evolution \n");
537 : 30 : fprintf (dump_file, " (scalar = ");
538 : 30 : print_generic_expr (dump_file, scalar);
539 : 30 : fprintf (dump_file, ")\n");
540 : : }
541 : 591232 : if (dump_flags & TDF_STATS)
542 : 50493 : nb_get_scev++;
543 : : }
544 : :
545 : 175535621 : if (VECTOR_TYPE_P (TREE_TYPE (scalar))
546 : 175535621 : || TREE_CODE (TREE_TYPE (scalar)) == COMPLEX_TYPE)
547 : : /* For chrec_dont_know we keep the symbolic form. */
548 : : res = scalar;
549 : : else
550 : 175270263 : switch (TREE_CODE (scalar))
551 : : {
552 : 142765862 : case SSA_NAME:
553 : 142765862 : if (SSA_NAME_IS_DEFAULT_DEF (scalar))
554 : : res = scalar;
555 : : else
556 : 140798589 : res = *find_var_scev_info (instantiated_below, scalar);
557 : : break;
558 : :
559 : : case REAL_CST:
560 : : case FIXED_CST:
561 : : case INTEGER_CST:
562 : : res = scalar;
563 : : break;
564 : :
565 : : default:
566 : 175535621 : res = chrec_not_analyzed_yet;
567 : : break;
568 : : }
569 : :
570 : 175535621 : if (dump_file && (dump_flags & TDF_SCEV))
571 : : {
572 : 30 : fprintf (dump_file, " (scalar_evolution = ");
573 : 30 : print_generic_expr (dump_file, res);
574 : 30 : fprintf (dump_file, "))\n");
575 : : }
576 : :
577 : 175535621 : return res;
578 : : }
579 : :
580 : :
581 : : /* Depth first search algorithm. */
582 : :
583 : : enum t_bool {
584 : : t_false,
585 : : t_true,
586 : : t_dont_know
587 : : };
588 : :
589 : : class scev_dfs
590 : : {
591 : : public:
592 : 9658216 : scev_dfs (class loop *loop_, gphi *phi_, tree init_cond_)
593 : 9658216 : : loop (loop_), loop_phi_node (phi_), init_cond (init_cond_) {}
594 : : t_bool get_ev (tree *, tree);
595 : :
596 : : private:
597 : : t_bool follow_ssa_edge_expr (gimple *, tree, tree *, int);
598 : : t_bool follow_ssa_edge_binary (gimple *at_stmt,
599 : : tree type, tree rhs0, enum tree_code code,
600 : : tree rhs1, tree *evolution_of_loop, int limit);
601 : : t_bool follow_ssa_edge_in_condition_phi_branch (int i,
602 : : gphi *condition_phi,
603 : : tree *evolution_of_branch,
604 : : tree init_cond, int limit);
605 : : t_bool follow_ssa_edge_in_condition_phi (gphi *condition_phi,
606 : : tree *evolution_of_loop, int limit);
607 : : t_bool follow_ssa_edge_inner_loop_phi (gphi *loop_phi_node,
608 : : tree *evolution_of_loop, int limit);
609 : : tree add_to_evolution (tree chrec_before, enum tree_code code,
610 : : tree to_add, gimple *at_stmt);
611 : : tree add_to_evolution_1 (tree chrec_before, tree to_add, gimple *at_stmt);
612 : :
613 : : class loop *loop;
614 : : gphi *loop_phi_node;
615 : : tree init_cond;
616 : : };
617 : :
618 : : t_bool
619 : 9658216 : scev_dfs::get_ev (tree *ev_fn, tree arg)
620 : : {
621 : 9658216 : *ev_fn = chrec_dont_know;
622 : 9658216 : return follow_ssa_edge_expr (loop_phi_node, arg, ev_fn, 0);
623 : : }
624 : :
625 : : /* Helper function for add_to_evolution. Returns the evolution
626 : : function for an assignment of the form "a = b + c", where "a" and
627 : : "b" are on the strongly connected component. CHREC_BEFORE is the
628 : : information that we already have collected up to this point.
629 : : TO_ADD is the evolution of "c".
630 : :
631 : : When CHREC_BEFORE has an evolution part in LOOP_NB, add to this
632 : : evolution the expression TO_ADD, otherwise construct an evolution
633 : : part for this loop. */
634 : :
635 : : tree
636 : 7946993 : scev_dfs::add_to_evolution_1 (tree chrec_before, tree to_add, gimple *at_stmt)
637 : : {
638 : 7946993 : tree type, left, right;
639 : 7946993 : unsigned loop_nb = loop->num;
640 : 7946993 : class loop *chloop;
641 : :
642 : 7946993 : switch (TREE_CODE (chrec_before))
643 : : {
644 : 100701 : case POLYNOMIAL_CHREC:
645 : 100701 : chloop = get_chrec_loop (chrec_before);
646 : 100701 : if (chloop == loop
647 : 100701 : || flow_loop_nested_p (chloop, loop))
648 : : {
649 : 100701 : unsigned var;
650 : :
651 : 100701 : type = chrec_type (chrec_before);
652 : :
653 : : /* When there is no evolution part in this loop, build it. */
654 : 100701 : if (chloop != loop)
655 : : {
656 : 0 : var = loop_nb;
657 : 0 : left = chrec_before;
658 : 0 : right = SCALAR_FLOAT_TYPE_P (type)
659 : 0 : ? build_real (type, dconst0)
660 : 0 : : build_int_cst (type, 0);
661 : : }
662 : : else
663 : : {
664 : 100701 : var = CHREC_VARIABLE (chrec_before);
665 : 100701 : left = CHREC_LEFT (chrec_before);
666 : 100701 : right = CHREC_RIGHT (chrec_before);
667 : : }
668 : :
669 : 100701 : to_add = chrec_convert (type, to_add, at_stmt);
670 : 100701 : right = chrec_convert_rhs (type, right, at_stmt);
671 : 100701 : right = chrec_fold_plus (chrec_type (right), right, to_add);
672 : 100701 : return build_polynomial_chrec (var, left, right);
673 : : }
674 : : else
675 : : {
676 : 0 : gcc_assert (flow_loop_nested_p (loop, chloop));
677 : :
678 : : /* Search the evolution in LOOP_NB. */
679 : 0 : left = add_to_evolution_1 (CHREC_LEFT (chrec_before),
680 : : to_add, at_stmt);
681 : 0 : right = CHREC_RIGHT (chrec_before);
682 : 0 : right = chrec_convert_rhs (chrec_type (left), right, at_stmt);
683 : 0 : return build_polynomial_chrec (CHREC_VARIABLE (chrec_before),
684 : 0 : left, right);
685 : : }
686 : :
687 : 7846292 : default:
688 : : /* These nodes do not depend on a loop. */
689 : 7846292 : if (chrec_before == chrec_dont_know)
690 : : return chrec_dont_know;
691 : :
692 : 7824725 : left = chrec_before;
693 : 7824725 : right = chrec_convert_rhs (chrec_type (left), to_add, at_stmt);
694 : : /* When we add the first evolution we need to replace the symbolic
695 : : evolution we've put in when the DFS reached the loop PHI node
696 : : with the initial value. There's only a limited cases of
697 : : extra operations ontop of that symbol allowed, namely
698 : : sign-conversions we can look through. For other cases we leave
699 : : the symbolic initial condition which causes build_polynomial_chrec
700 : : to return chrec_dont_know. See PR42512, PR66375 and PR107176 for
701 : : cases we mishandled before. */
702 : 7824725 : STRIP_NOPS (chrec_before);
703 : 7824725 : if (chrec_before == gimple_phi_result (loop_phi_node))
704 : 7824015 : left = fold_convert (TREE_TYPE (left), init_cond);
705 : 7824725 : return build_polynomial_chrec (loop_nb, left, right);
706 : : }
707 : : }
708 : :
709 : : /* Add TO_ADD to the evolution part of CHREC_BEFORE in the dimension
710 : : of LOOP_NB.
711 : :
712 : : Description (provided for completeness, for those who read code in
713 : : a plane, and for my poor 62 bytes brain that would have forgotten
714 : : all this in the next two or three months):
715 : :
716 : : The algorithm of translation of programs from the SSA representation
717 : : into the chrecs syntax is based on a pattern matching. After having
718 : : reconstructed the overall tree expression for a loop, there are only
719 : : two cases that can arise:
720 : :
721 : : 1. a = loop-phi (init, a + expr)
722 : : 2. a = loop-phi (init, expr)
723 : :
724 : : where EXPR is either a scalar constant with respect to the analyzed
725 : : loop (this is a degree 0 polynomial), or an expression containing
726 : : other loop-phi definitions (these are higher degree polynomials).
727 : :
728 : : Examples:
729 : :
730 : : 1.
731 : : | init = ...
732 : : | loop_1
733 : : | a = phi (init, a + 5)
734 : : | endloop
735 : :
736 : : 2.
737 : : | inita = ...
738 : : | initb = ...
739 : : | loop_1
740 : : | a = phi (inita, 2 * b + 3)
741 : : | b = phi (initb, b + 1)
742 : : | endloop
743 : :
744 : : For the first case, the semantics of the SSA representation is:
745 : :
746 : : | a (x) = init + \sum_{j = 0}^{x - 1} expr (j)
747 : :
748 : : that is, there is a loop index "x" that determines the scalar value
749 : : of the variable during the loop execution. During the first
750 : : iteration, the value is that of the initial condition INIT, while
751 : : during the subsequent iterations, it is the sum of the initial
752 : : condition with the sum of all the values of EXPR from the initial
753 : : iteration to the before last considered iteration.
754 : :
755 : : For the second case, the semantics of the SSA program is:
756 : :
757 : : | a (x) = init, if x = 0;
758 : : | expr (x - 1), otherwise.
759 : :
760 : : The second case corresponds to the PEELED_CHREC, whose syntax is
761 : : close to the syntax of a loop-phi-node:
762 : :
763 : : | phi (init, expr) vs. (init, expr)_x
764 : :
765 : : The proof of the translation algorithm for the first case is a
766 : : proof by structural induction based on the degree of EXPR.
767 : :
768 : : Degree 0:
769 : : When EXPR is a constant with respect to the analyzed loop, or in
770 : : other words when EXPR is a polynomial of degree 0, the evolution of
771 : : the variable A in the loop is an affine function with an initial
772 : : condition INIT, and a step EXPR. In order to show this, we start
773 : : from the semantics of the SSA representation:
774 : :
775 : : f (x) = init + \sum_{j = 0}^{x - 1} expr (j)
776 : :
777 : : and since "expr (j)" is a constant with respect to "j",
778 : :
779 : : f (x) = init + x * expr
780 : :
781 : : Finally, based on the semantics of the pure sum chrecs, by
782 : : identification we get the corresponding chrecs syntax:
783 : :
784 : : f (x) = init * \binom{x}{0} + expr * \binom{x}{1}
785 : : f (x) -> {init, +, expr}_x
786 : :
787 : : Higher degree:
788 : : Suppose that EXPR is a polynomial of degree N with respect to the
789 : : analyzed loop_x for which we have already determined that it is
790 : : written under the chrecs syntax:
791 : :
792 : : | expr (x) -> {b_0, +, b_1, +, ..., +, b_{n-1}} (x)
793 : :
794 : : We start from the semantics of the SSA program:
795 : :
796 : : | f (x) = init + \sum_{j = 0}^{x - 1} expr (j)
797 : : |
798 : : | f (x) = init + \sum_{j = 0}^{x - 1}
799 : : | (b_0 * \binom{j}{0} + ... + b_{n-1} * \binom{j}{n-1})
800 : : |
801 : : | f (x) = init + \sum_{j = 0}^{x - 1}
802 : : | \sum_{k = 0}^{n - 1} (b_k * \binom{j}{k})
803 : : |
804 : : | f (x) = init + \sum_{k = 0}^{n - 1}
805 : : | (b_k * \sum_{j = 0}^{x - 1} \binom{j}{k})
806 : : |
807 : : | f (x) = init + \sum_{k = 0}^{n - 1}
808 : : | (b_k * \binom{x}{k + 1})
809 : : |
810 : : | f (x) = init + b_0 * \binom{x}{1} + ...
811 : : | + b_{n-1} * \binom{x}{n}
812 : : |
813 : : | f (x) = init * \binom{x}{0} + b_0 * \binom{x}{1} + ...
814 : : | + b_{n-1} * \binom{x}{n}
815 : : |
816 : :
817 : : And finally from the definition of the chrecs syntax, we identify:
818 : : | f (x) -> {init, +, b_0, +, ..., +, b_{n-1}}_x
819 : :
820 : : This shows the mechanism that stands behind the add_to_evolution
821 : : function. An important point is that the use of symbolic
822 : : parameters avoids the need of an analysis schedule.
823 : :
824 : : Example:
825 : :
826 : : | inita = ...
827 : : | initb = ...
828 : : | loop_1
829 : : | a = phi (inita, a + 2 + b)
830 : : | b = phi (initb, b + 1)
831 : : | endloop
832 : :
833 : : When analyzing "a", the algorithm keeps "b" symbolically:
834 : :
835 : : | a -> {inita, +, 2 + b}_1
836 : :
837 : : Then, after instantiation, the analyzer ends on the evolution:
838 : :
839 : : | a -> {inita, +, 2 + initb, +, 1}_1
840 : :
841 : : */
842 : :
843 : : tree
844 : 7946993 : scev_dfs::add_to_evolution (tree chrec_before, enum tree_code code,
845 : : tree to_add, gimple *at_stmt)
846 : : {
847 : 7946993 : tree type = chrec_type (to_add);
848 : 7946993 : tree res = NULL_TREE;
849 : :
850 : 7946993 : if (to_add == NULL_TREE)
851 : : return chrec_before;
852 : :
853 : : /* TO_ADD is either a scalar, or a parameter. TO_ADD is not
854 : : instantiated at this point. */
855 : 7946993 : if (TREE_CODE (to_add) == POLYNOMIAL_CHREC)
856 : : /* This should not happen. */
857 : 0 : return chrec_dont_know;
858 : :
859 : 7946993 : if (dump_file && (dump_flags & TDF_SCEV))
860 : : {
861 : 0 : fprintf (dump_file, "(add_to_evolution \n");
862 : 0 : fprintf (dump_file, " (loop_nb = %d)\n", loop->num);
863 : 0 : fprintf (dump_file, " (chrec_before = ");
864 : 0 : print_generic_expr (dump_file, chrec_before);
865 : 0 : fprintf (dump_file, ")\n (to_add = ");
866 : 0 : print_generic_expr (dump_file, to_add);
867 : 0 : fprintf (dump_file, ")\n");
868 : : }
869 : :
870 : 7946993 : if (code == MINUS_EXPR)
871 : 1403120 : to_add = chrec_fold_multiply (type, to_add, SCALAR_FLOAT_TYPE_P (type)
872 : 4895 : ? build_real (type, dconstm1)
873 : 1398225 : : build_int_cst_type (type, -1));
874 : :
875 : 7946993 : res = add_to_evolution_1 (chrec_before, to_add, at_stmt);
876 : :
877 : 7946993 : if (dump_file && (dump_flags & TDF_SCEV))
878 : : {
879 : 0 : fprintf (dump_file, " (res = ");
880 : 0 : print_generic_expr (dump_file, res);
881 : 0 : fprintf (dump_file, "))\n");
882 : : }
883 : :
884 : : return res;
885 : : }
886 : :
887 : :
888 : : /* Follow the ssa edge into the binary expression RHS0 CODE RHS1.
889 : : Return true if the strongly connected component has been found. */
890 : :
891 : : t_bool
892 : 968438 : scev_dfs::follow_ssa_edge_binary (gimple *at_stmt, tree type, tree rhs0,
893 : : enum tree_code code, tree rhs1,
894 : : tree *evolution_of_loop, int limit)
895 : : {
896 : 968438 : t_bool res = t_false;
897 : 968438 : tree evol;
898 : :
899 : 968438 : switch (code)
900 : : {
901 : 964354 : case POINTER_PLUS_EXPR:
902 : 964354 : case PLUS_EXPR:
903 : 964354 : if (TREE_CODE (rhs0) == SSA_NAME)
904 : : {
905 : 950438 : if (TREE_CODE (rhs1) == SSA_NAME)
906 : : {
907 : : /* Match an assignment under the form:
908 : : "a = b + c". */
909 : :
910 : : /* We want only assignments of form "name + name" contribute to
911 : : LIMIT, as the other cases do not necessarily contribute to
912 : : the complexity of the expression. */
913 : 950438 : limit++;
914 : :
915 : 950438 : evol = *evolution_of_loop;
916 : 950438 : res = follow_ssa_edge_expr (at_stmt, rhs0, &evol, limit);
917 : 950438 : if (res == t_true)
918 : 398270 : *evolution_of_loop = add_to_evolution
919 : 398270 : (chrec_convert (type, evol, at_stmt), code, rhs1, at_stmt);
920 : 552168 : else if (res == t_false)
921 : : {
922 : 535832 : res = follow_ssa_edge_expr
923 : 535832 : (at_stmt, rhs1, evolution_of_loop, limit);
924 : 535832 : if (res == t_true)
925 : 395923 : *evolution_of_loop = add_to_evolution
926 : 395923 : (chrec_convert (type, *evolution_of_loop, at_stmt),
927 : : code, rhs0, at_stmt);
928 : : }
929 : : }
930 : :
931 : : else
932 : 0 : gcc_unreachable (); /* Handled in caller. */
933 : : }
934 : :
935 : 13916 : else if (TREE_CODE (rhs1) == SSA_NAME)
936 : : {
937 : : /* Match an assignment under the form:
938 : : "a = ... + c". */
939 : 5555 : res = follow_ssa_edge_expr (at_stmt, rhs1, evolution_of_loop, limit);
940 : 5555 : if (res == t_true)
941 : 4852 : *evolution_of_loop = add_to_evolution
942 : 4852 : (chrec_convert (type, *evolution_of_loop, at_stmt),
943 : : code, rhs0, at_stmt);
944 : : }
945 : :
946 : : else
947 : : /* Otherwise, match an assignment under the form:
948 : : "a = ... + ...". */
949 : : /* And there is nothing to do. */
950 : : res = t_false;
951 : : break;
952 : :
953 : 4084 : case MINUS_EXPR:
954 : : /* This case is under the form "opnd0 = rhs0 - rhs1". */
955 : 4084 : if (TREE_CODE (rhs0) == SSA_NAME)
956 : 0 : gcc_unreachable (); /* Handled in caller. */
957 : : else
958 : : /* Otherwise, match an assignment under the form:
959 : : "a = ... - ...". */
960 : : /* And there is nothing to do. */
961 : : res = t_false;
962 : : break;
963 : :
964 : : default:
965 : : res = t_false;
966 : : }
967 : :
968 : 968438 : return res;
969 : : }
970 : :
971 : : /* Checks whether the I-th argument of a PHI comes from a backedge. */
972 : :
973 : : static bool
974 : 7613780 : backedge_phi_arg_p (gphi *phi, int i)
975 : : {
976 : 7613780 : const_edge e = gimple_phi_arg_edge (phi, i);
977 : :
978 : : /* We would in fact like to test EDGE_DFS_BACK here, but we do not care
979 : : about updating it anywhere, and this should work as well most of the
980 : : time. */
981 : 7613780 : if (e->flags & EDGE_IRREDUCIBLE_LOOP)
982 : 46611 : return true;
983 : :
984 : : return false;
985 : : }
986 : :
987 : : /* Helper function for one branch of the condition-phi-node. Return
988 : : true if the strongly connected component has been found following
989 : : this path. */
990 : :
991 : : t_bool
992 : 3052861 : scev_dfs::follow_ssa_edge_in_condition_phi_branch (int i,
993 : : gphi *condition_phi,
994 : : tree *evolution_of_branch,
995 : : tree init_cond, int limit)
996 : : {
997 : 3052861 : tree branch = PHI_ARG_DEF (condition_phi, i);
998 : 3052861 : *evolution_of_branch = chrec_dont_know;
999 : :
1000 : : /* Do not follow back edges (they must belong to an irreducible loop, which
1001 : : we really do not want to worry about). */
1002 : 3052861 : if (backedge_phi_arg_p (condition_phi, i))
1003 : : return t_false;
1004 : :
1005 : 3047331 : if (TREE_CODE (branch) == SSA_NAME)
1006 : : {
1007 : 2833920 : *evolution_of_branch = init_cond;
1008 : 2833920 : return follow_ssa_edge_expr (condition_phi, branch,
1009 : 2833920 : evolution_of_branch, limit);
1010 : : }
1011 : :
1012 : : /* This case occurs when one of the condition branches sets
1013 : : the variable to a constant: i.e. a phi-node like
1014 : : "a_2 = PHI <a_7(5), 2(6)>;".
1015 : :
1016 : : FIXME: This case have to be refined correctly:
1017 : : in some cases it is possible to say something better than
1018 : : chrec_dont_know, for example using a wrap-around notation. */
1019 : : return t_false;
1020 : : }
1021 : :
1022 : : /* This function merges the branches of a condition-phi-node in a
1023 : : loop. */
1024 : :
1025 : : t_bool
1026 : 1985984 : scev_dfs::follow_ssa_edge_in_condition_phi (gphi *condition_phi,
1027 : : tree *evolution_of_loop, int limit)
1028 : : {
1029 : 1985984 : int i, n;
1030 : 1985984 : tree init = *evolution_of_loop;
1031 : 1985984 : tree evolution_of_branch;
1032 : 1985984 : t_bool res = follow_ssa_edge_in_condition_phi_branch (0, condition_phi,
1033 : : &evolution_of_branch,
1034 : : init, limit);
1035 : 1985984 : if (res == t_false || res == t_dont_know)
1036 : : return res;
1037 : :
1038 : 1088831 : *evolution_of_loop = evolution_of_branch;
1039 : :
1040 : 1088831 : n = gimple_phi_num_args (condition_phi);
1041 : 1575868 : for (i = 1; i < n; i++)
1042 : : {
1043 : : /* Quickly give up when the evolution of one of the branches is
1044 : : not known. */
1045 : 1180008 : if (*evolution_of_loop == chrec_dont_know)
1046 : : return t_true;
1047 : :
1048 : : /* Increase the limit by the PHI argument number to avoid exponential
1049 : : time and memory complexity. */
1050 : 1066877 : res = follow_ssa_edge_in_condition_phi_branch (i, condition_phi,
1051 : : &evolution_of_branch,
1052 : : init, limit + i);
1053 : 1066877 : if (res == t_false || res == t_dont_know)
1054 : : return res;
1055 : :
1056 : 487037 : *evolution_of_loop = chrec_merge (*evolution_of_loop,
1057 : : evolution_of_branch);
1058 : : }
1059 : :
1060 : : return t_true;
1061 : : }
1062 : :
1063 : : /* Follow an SSA edge in an inner loop. It computes the overall
1064 : : effect of the loop, and following the symbolic initial conditions,
1065 : : it follows the edges in the parent loop. The inner loop is
1066 : : considered as a single statement. */
1067 : :
1068 : : t_bool
1069 : 239857 : scev_dfs::follow_ssa_edge_inner_loop_phi (gphi *loop_phi_node,
1070 : : tree *evolution_of_loop, int limit)
1071 : : {
1072 : 239857 : class loop *loop = loop_containing_stmt (loop_phi_node);
1073 : 239857 : tree ev = analyze_scalar_evolution (loop, PHI_RESULT (loop_phi_node));
1074 : :
1075 : : /* Sometimes, the inner loop is too difficult to analyze, and the
1076 : : result of the analysis is a symbolic parameter. */
1077 : 239857 : if (ev == PHI_RESULT (loop_phi_node))
1078 : : {
1079 : 102275 : t_bool res = t_false;
1080 : 102275 : int i, n = gimple_phi_num_args (loop_phi_node);
1081 : :
1082 : 146690 : for (i = 0; i < n; i++)
1083 : : {
1084 : 138701 : tree arg = PHI_ARG_DEF (loop_phi_node, i);
1085 : 138701 : basic_block bb;
1086 : :
1087 : : /* Follow the edges that exit the inner loop. */
1088 : 138701 : bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1089 : 138701 : if (!flow_bb_inside_loop_p (loop, bb))
1090 : 102275 : res = follow_ssa_edge_expr (loop_phi_node,
1091 : : arg, evolution_of_loop, limit);
1092 : 138701 : if (res == t_true)
1093 : : break;
1094 : : }
1095 : :
1096 : : /* If the path crosses this loop-phi, give up. */
1097 : 102275 : if (res == t_true)
1098 : 94286 : *evolution_of_loop = chrec_dont_know;
1099 : :
1100 : 102275 : return res;
1101 : : }
1102 : :
1103 : : /* Otherwise, compute the overall effect of the inner loop. */
1104 : 137582 : ev = compute_overall_effect_of_inner_loop (loop, ev);
1105 : 137582 : return follow_ssa_edge_expr (loop_phi_node, ev, evolution_of_loop, limit);
1106 : : }
1107 : :
1108 : : /* Follow the ssa edge into the expression EXPR.
1109 : : Return true if the strongly connected component has been found. */
1110 : :
1111 : : t_bool
1112 : 21799794 : scev_dfs::follow_ssa_edge_expr (gimple *at_stmt, tree expr,
1113 : : tree *evolution_of_loop, int limit)
1114 : : {
1115 : 21799794 : gphi *halting_phi = loop_phi_node;
1116 : 21799794 : enum tree_code code;
1117 : 21799794 : tree type, rhs0, rhs1 = NULL_TREE;
1118 : :
1119 : : /* The EXPR is one of the following cases:
1120 : : - an SSA_NAME,
1121 : : - an INTEGER_CST,
1122 : : - a PLUS_EXPR,
1123 : : - a POINTER_PLUS_EXPR,
1124 : : - a MINUS_EXPR,
1125 : : - other cases are not yet handled. */
1126 : :
1127 : : /* For SSA_NAME look at the definition statement, handling
1128 : : PHI nodes and otherwise expand appropriately for the expression
1129 : : handling below. */
1130 : 21799794 : if (TREE_CODE (expr) == SSA_NAME)
1131 : : {
1132 : 21651059 : gimple *def = SSA_NAME_DEF_STMT (expr);
1133 : :
1134 : 21651059 : if (gimple_nop_p (def))
1135 : : return t_false;
1136 : :
1137 : : /* Give up if the path is longer than the MAX that we allow. */
1138 : 21635672 : if (limit > param_scev_max_expr_complexity)
1139 : : {
1140 : 6405 : *evolution_of_loop = chrec_dont_know;
1141 : 6405 : return t_dont_know;
1142 : : }
1143 : :
1144 : 21629267 : if (gphi *phi = dyn_cast <gphi *>(def))
1145 : : {
1146 : 22493682 : if (!loop_phi_node_p (phi))
1147 : : /* DEF is a condition-phi-node. Follow the branches, and
1148 : : record their evolutions. Finally, merge the collected
1149 : : information and set the approximation to the main
1150 : : variable. */
1151 : 1985984 : return follow_ssa_edge_in_condition_phi (phi, evolution_of_loop,
1152 : 1985984 : limit);
1153 : :
1154 : : /* When the analyzed phi is the halting_phi, the
1155 : : depth-first search is over: we have found a path from
1156 : : the halting_phi to itself in the loop. */
1157 : 9260857 : if (phi == halting_phi)
1158 : : {
1159 : 8851930 : *evolution_of_loop = expr;
1160 : 8851930 : return t_true;
1161 : : }
1162 : :
1163 : : /* Otherwise, the evolution of the HALTING_PHI depends
1164 : : on the evolution of another loop-phi-node, i.e. the
1165 : : evolution function is a higher degree polynomial. */
1166 : 408927 : class loop *def_loop = loop_containing_stmt (def);
1167 : 408927 : if (def_loop == loop)
1168 : : return t_false;
1169 : :
1170 : : /* Inner loop. */
1171 : 259476 : if (flow_loop_nested_p (loop, def_loop))
1172 : 239857 : return follow_ssa_edge_inner_loop_phi (phi, evolution_of_loop,
1173 : 239857 : limit + 1);
1174 : :
1175 : : /* Outer loop. */
1176 : : return t_false;
1177 : : }
1178 : :
1179 : : /* At this level of abstraction, the program is just a set
1180 : : of GIMPLE_ASSIGNs and PHI_NODEs. In principle there is no
1181 : : other def to be handled. */
1182 : 10382426 : if (!is_gimple_assign (def))
1183 : : return t_false;
1184 : :
1185 : 10282634 : code = gimple_assign_rhs_code (def);
1186 : 10282634 : switch (get_gimple_rhs_class (code))
1187 : : {
1188 : 8945293 : case GIMPLE_BINARY_RHS:
1189 : 8945293 : rhs0 = gimple_assign_rhs1 (def);
1190 : 8945293 : rhs1 = gimple_assign_rhs2 (def);
1191 : 8945293 : break;
1192 : 1325072 : case GIMPLE_UNARY_RHS:
1193 : 1325072 : case GIMPLE_SINGLE_RHS:
1194 : 1325072 : rhs0 = gimple_assign_rhs1 (def);
1195 : 1325072 : break;
1196 : : default:
1197 : : return t_false;
1198 : : }
1199 : 10270365 : type = TREE_TYPE (gimple_assign_lhs (def));
1200 : 10270365 : at_stmt = def;
1201 : : }
1202 : : else
1203 : : {
1204 : 148735 : code = TREE_CODE (expr);
1205 : 148735 : type = TREE_TYPE (expr);
1206 : : /* Via follow_ssa_edge_inner_loop_phi we arrive here with the
1207 : : GENERIC scalar evolution of the inner loop. */
1208 : 148735 : switch (code)
1209 : : {
1210 : 9727 : CASE_CONVERT:
1211 : 9727 : rhs0 = TREE_OPERAND (expr, 0);
1212 : 9727 : break;
1213 : 18836 : case POINTER_PLUS_EXPR:
1214 : 18836 : case PLUS_EXPR:
1215 : 18836 : case MINUS_EXPR:
1216 : 18836 : rhs0 = TREE_OPERAND (expr, 0);
1217 : 18836 : rhs1 = TREE_OPERAND (expr, 1);
1218 : 18836 : STRIP_USELESS_TYPE_CONVERSION (rhs0);
1219 : 18836 : STRIP_USELESS_TYPE_CONVERSION (rhs1);
1220 : 18836 : break;
1221 : : default:
1222 : : rhs0 = expr;
1223 : : }
1224 : : }
1225 : :
1226 : 10419100 : switch (code)
1227 : : {
1228 : 309248 : CASE_CONVERT:
1229 : 309248 : {
1230 : : /* This assignment is under the form "a_1 = (cast) rhs. We cannot
1231 : : validate any precision altering conversion during the SCC
1232 : : analysis, so don't even try. */
1233 : 309248 : if (!tree_nop_conversion_p (type, TREE_TYPE (rhs0)))
1234 : : return t_false;
1235 : 208030 : t_bool res = follow_ssa_edge_expr (at_stmt, rhs0,
1236 : : evolution_of_loop, limit);
1237 : 208030 : if (res == t_true)
1238 : 100420 : *evolution_of_loop = chrec_convert (type, *evolution_of_loop,
1239 : : at_stmt);
1240 : : return res;
1241 : : }
1242 : :
1243 : : case INTEGER_CST:
1244 : : /* This assignment is under the form "a_1 = 7". */
1245 : : return t_false;
1246 : :
1247 : 1966 : case ADDR_EXPR:
1248 : 1966 : {
1249 : : /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. */
1250 : 1966 : if (TREE_CODE (TREE_OPERAND (rhs0, 0)) != MEM_REF)
1251 : : return t_false;
1252 : 0 : tree mem = TREE_OPERAND (rhs0, 0);
1253 : 0 : rhs0 = TREE_OPERAND (mem, 0);
1254 : 0 : rhs1 = TREE_OPERAND (mem, 1);
1255 : 0 : code = POINTER_PLUS_EXPR;
1256 : : }
1257 : : /* Fallthru. */
1258 : 8336384 : case POINTER_PLUS_EXPR:
1259 : 8336384 : case PLUS_EXPR:
1260 : 8336384 : case MINUS_EXPR:
1261 : : /* This case is under the form "rhs0 +- rhs1". */
1262 : 8336384 : if (TREE_CODE (rhs0) == SSA_NAME
1263 : 8318384 : && (TREE_CODE (rhs1) != SSA_NAME || code == MINUS_EXPR))
1264 : : {
1265 : : /* Match an assignment under the form:
1266 : : "a = b +- ...". */
1267 : 7367946 : t_bool res = follow_ssa_edge_expr (at_stmt, rhs0,
1268 : : evolution_of_loop, limit);
1269 : 7367946 : if (res == t_true)
1270 : 7147948 : *evolution_of_loop = add_to_evolution
1271 : 7147948 : (chrec_convert (type, *evolution_of_loop, at_stmt),
1272 : : code, rhs1, at_stmt);
1273 : 7367946 : return res;
1274 : : }
1275 : : /* Else search for the SCC in both rhs0 and rhs1. */
1276 : 968438 : return follow_ssa_edge_binary (at_stmt, type, rhs0, code, rhs1,
1277 : 968438 : evolution_of_loop, limit);
1278 : :
1279 : : default:
1280 : : return t_false;
1281 : : }
1282 : : }
1283 : :
1284 : :
1285 : : /* This section selects the loops that will be good candidates for the
1286 : : scalar evolution analysis. For the moment, greedily select all the
1287 : : loop nests we could analyze. */
1288 : :
1289 : : /* For a loop with a single exit edge, return the COND_EXPR that
1290 : : guards the exit edge. If the expression is too difficult to
1291 : : analyze, then give up. */
1292 : :
1293 : : gcond *
1294 : 219 : get_loop_exit_condition (const class loop *loop)
1295 : : {
1296 : 219 : return get_loop_exit_condition (single_exit (loop));
1297 : : }
1298 : :
1299 : : /* If the statement just before the EXIT_EDGE contains a condition then
1300 : : return the condition, otherwise NULL. */
1301 : :
1302 : : gcond *
1303 : 4720650 : get_loop_exit_condition (const_edge exit_edge)
1304 : : {
1305 : 4720650 : gcond *res = NULL;
1306 : :
1307 : 4720650 : if (dump_file && (dump_flags & TDF_SCEV))
1308 : 2 : fprintf (dump_file, "(get_loop_exit_condition \n ");
1309 : :
1310 : 4720650 : if (exit_edge)
1311 : 14161950 : res = safe_dyn_cast <gcond *> (*gsi_last_bb (exit_edge->src));
1312 : :
1313 : 4720650 : if (dump_file && (dump_flags & TDF_SCEV))
1314 : : {
1315 : 2 : print_gimple_stmt (dump_file, res, 0);
1316 : 2 : fprintf (dump_file, ")\n");
1317 : : }
1318 : :
1319 : 4720650 : return res;
1320 : : }
1321 : :
1322 : :
1323 : : /* Simplify PEELED_CHREC represented by (init_cond, arg) in LOOP.
1324 : : Handle below case and return the corresponding POLYNOMIAL_CHREC:
1325 : :
1326 : : # i_17 = PHI <i_13(5), 0(3)>
1327 : : # _20 = PHI <_5(5), start_4(D)(3)>
1328 : : ...
1329 : : i_13 = i_17 + 1;
1330 : : _5 = start_4(D) + i_13;
1331 : :
1332 : : Though variable _20 appears as a PEELED_CHREC in the form of
1333 : : (start_4, _5)_LOOP, it's a POLYNOMIAL_CHREC like {start_4, 1}_LOOP.
1334 : :
1335 : : See PR41488. */
1336 : :
1337 : : static tree
1338 : 1355316 : simplify_peeled_chrec (class loop *loop, tree arg, tree init_cond)
1339 : : {
1340 : 2710632 : aff_tree aff1, aff2;
1341 : 1355316 : tree ev, left, right, type, step_val;
1342 : 1355316 : hash_map<tree, name_expansion *> *peeled_chrec_map = NULL;
1343 : :
1344 : 1355316 : ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, arg));
1345 : 1355316 : if (ev == NULL_TREE || TREE_CODE (ev) != POLYNOMIAL_CHREC)
1346 : 1329720 : return chrec_dont_know;
1347 : :
1348 : 25596 : left = CHREC_LEFT (ev);
1349 : 25596 : right = CHREC_RIGHT (ev);
1350 : 25596 : type = TREE_TYPE (left);
1351 : 25596 : step_val = chrec_fold_plus (type, init_cond, right);
1352 : :
1353 : : /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
1354 : : if "left" equals to "init + right". */
1355 : 25596 : if (operand_equal_p (left, step_val, 0))
1356 : : {
1357 : 9521 : if (dump_file && (dump_flags & TDF_SCEV))
1358 : 1 : fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
1359 : :
1360 : 9521 : return build_polynomial_chrec (loop->num, init_cond, right);
1361 : : }
1362 : :
1363 : : /* The affine code only deals with pointer and integer types. */
1364 : 16075 : if (!POINTER_TYPE_P (type)
1365 : 14513 : && !INTEGRAL_TYPE_P (type))
1366 : 15 : return chrec_dont_know;
1367 : :
1368 : : /* Try harder to check if they are equal. */
1369 : 16060 : tree_to_aff_combination_expand (left, type, &aff1, &peeled_chrec_map);
1370 : 16060 : tree_to_aff_combination_expand (step_val, type, &aff2, &peeled_chrec_map);
1371 : 16060 : free_affine_expand_cache (&peeled_chrec_map);
1372 : 16060 : aff_combination_scale (&aff2, -1);
1373 : 16060 : aff_combination_add (&aff1, &aff2);
1374 : :
1375 : : /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
1376 : : if "left" equals to "init + right". */
1377 : 16060 : if (aff_combination_zero_p (&aff1))
1378 : : {
1379 : 8717 : if (dump_file && (dump_flags & TDF_SCEV))
1380 : 1 : fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
1381 : :
1382 : 8717 : return build_polynomial_chrec (loop->num, init_cond, right);
1383 : : }
1384 : 7343 : return chrec_dont_know;
1385 : 1355316 : }
1386 : :
1387 : : /* Given a LOOP_PHI_NODE, this function determines the evolution
1388 : : function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop. */
1389 : :
1390 : : static tree
1391 : 9773710 : analyze_evolution_in_loop (gphi *loop_phi_node,
1392 : : tree init_cond)
1393 : : {
1394 : 9773710 : int i, n = gimple_phi_num_args (loop_phi_node);
1395 : 9773710 : tree evolution_function = chrec_not_analyzed_yet;
1396 : 9773710 : class loop *loop = loop_containing_stmt (loop_phi_node);
1397 : 9773710 : basic_block bb;
1398 : 9773710 : static bool simplify_peeled_chrec_p = true;
1399 : :
1400 : 9773710 : if (dump_file && (dump_flags & TDF_SCEV))
1401 : : {
1402 : 2 : fprintf (dump_file, "(analyze_evolution_in_loop \n");
1403 : 2 : fprintf (dump_file, " (loop_phi_node = ");
1404 : 2 : print_gimple_stmt (dump_file, loop_phi_node, 0);
1405 : 2 : fprintf (dump_file, ")\n");
1406 : : }
1407 : :
1408 : 25944606 : for (i = 0; i < n; i++)
1409 : : {
1410 : 18439926 : tree arg = PHI_ARG_DEF (loop_phi_node, i);
1411 : 18439926 : tree ev_fn = chrec_dont_know;
1412 : 18439926 : t_bool res;
1413 : :
1414 : : /* Select the edges that enter the loop body. */
1415 : 18439926 : bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1416 : 18439926 : if (!flow_bb_inside_loop_p (loop, bb))
1417 : 8666216 : continue;
1418 : :
1419 : 9773710 : if (TREE_CODE (arg) == SSA_NAME)
1420 : : {
1421 : 9658216 : bool val = false;
1422 : :
1423 : : /* Pass in the initial condition to the follow edge function. */
1424 : 9658216 : scev_dfs dfs (loop, loop_phi_node, init_cond);
1425 : 9658216 : res = dfs.get_ev (&ev_fn, arg);
1426 : :
1427 : : /* If ev_fn has no evolution in the inner loop, and the
1428 : : init_cond is not equal to ev_fn, then we have an
1429 : : ambiguity between two possible values, as we cannot know
1430 : : the number of iterations at this point. */
1431 : 9658216 : if (TREE_CODE (ev_fn) != POLYNOMIAL_CHREC
1432 : 2238262 : && no_evolution_in_loop_p (ev_fn, loop->num, &val) && val
1433 : 9658222 : && !operand_equal_p (init_cond, ev_fn, 0))
1434 : 0 : ev_fn = chrec_dont_know;
1435 : : }
1436 : : else
1437 : : res = t_false;
1438 : :
1439 : : /* When it is impossible to go back on the same
1440 : : loop_phi_node by following the ssa edges, the
1441 : : evolution is represented by a peeled chrec, i.e. the
1442 : : first iteration, EV_FN has the value INIT_COND, then
1443 : : all the other iterations it has the value of ARG.
1444 : : For the moment, PEELED_CHREC nodes are not built. */
1445 : 9658216 : if (res != t_true)
1446 : : {
1447 : 1988657 : ev_fn = chrec_dont_know;
1448 : : /* Try to recognize POLYNOMIAL_CHREC which appears in
1449 : : the form of PEELED_CHREC, but guard the process with
1450 : : a bool variable to keep the analyzer from infinite
1451 : : recurrence for real PEELED_RECs. */
1452 : 1988657 : if (simplify_peeled_chrec_p && TREE_CODE (arg) == SSA_NAME)
1453 : : {
1454 : 1355316 : simplify_peeled_chrec_p = false;
1455 : 1355316 : ev_fn = simplify_peeled_chrec (loop, arg, init_cond);
1456 : 1355316 : simplify_peeled_chrec_p = true;
1457 : : }
1458 : : }
1459 : :
1460 : : /* When there are multiple back edges of the loop (which in fact never
1461 : : happens currently, but nevertheless), merge their evolutions. */
1462 : 9773710 : evolution_function = chrec_merge (evolution_function, ev_fn);
1463 : :
1464 : 9773710 : if (evolution_function == chrec_dont_know)
1465 : : break;
1466 : : }
1467 : :
1468 : 9773710 : if (dump_file && (dump_flags & TDF_SCEV))
1469 : : {
1470 : 2 : fprintf (dump_file, " (evolution_function = ");
1471 : 2 : print_generic_expr (dump_file, evolution_function);
1472 : 2 : fprintf (dump_file, "))\n");
1473 : : }
1474 : :
1475 : 9773710 : return evolution_function;
1476 : : }
1477 : :
1478 : : /* Looks to see if VAR is a copy of a constant (via straightforward assignments
1479 : : or degenerate phi's). If so, returns the constant; else, returns VAR. */
1480 : :
1481 : : static tree
1482 : 20334192 : follow_copies_to_constant (tree var)
1483 : : {
1484 : 20334192 : tree res = var;
1485 : 20334192 : while (TREE_CODE (res) == SSA_NAME
1486 : : /* We face not updated SSA form in multiple places and this walk
1487 : : may end up in sibling loops so we have to guard it. */
1488 : 24488929 : && !name_registered_for_update_p (res))
1489 : : {
1490 : 14635440 : gimple *def = SSA_NAME_DEF_STMT (res);
1491 : 14635440 : if (gphi *phi = dyn_cast <gphi *> (def))
1492 : : {
1493 : 4118556 : if (tree rhs = degenerate_phi_result (phi))
1494 : : res = rhs;
1495 : : else
1496 : : break;
1497 : : }
1498 : 10516884 : else if (gimple_assign_single_p (def))
1499 : : /* Will exit loop if not an SSA_NAME. */
1500 : 3753635 : res = gimple_assign_rhs1 (def);
1501 : : else
1502 : : break;
1503 : : }
1504 : 20334192 : if (CONSTANT_CLASS_P (res))
1505 : 5989491 : return res;
1506 : : return var;
1507 : : }
1508 : :
1509 : : /* Given a loop-phi-node, return the initial conditions of the
1510 : : variable on entry of the loop. When the CCP has propagated
1511 : : constants into the loop-phi-node, the initial condition is
1512 : : instantiated, otherwise the initial condition is kept symbolic.
1513 : : This analyzer does not analyze the evolution outside the current
1514 : : loop, and leaves this task to the on-demand tree reconstructor. */
1515 : :
1516 : : static tree
1517 : 9773710 : analyze_initial_condition (gphi *loop_phi_node)
1518 : : {
1519 : 9773710 : int i, n;
1520 : 9773710 : tree init_cond = chrec_not_analyzed_yet;
1521 : 9773710 : class loop *loop = loop_containing_stmt (loop_phi_node);
1522 : :
1523 : 9773710 : if (dump_file && (dump_flags & TDF_SCEV))
1524 : : {
1525 : 2 : fprintf (dump_file, "(analyze_initial_condition \n");
1526 : 2 : fprintf (dump_file, " (loop_phi_node = \n");
1527 : 2 : print_gimple_stmt (dump_file, loop_phi_node, 0);
1528 : 2 : fprintf (dump_file, ")\n");
1529 : : }
1530 : :
1531 : 9773710 : n = gimple_phi_num_args (loop_phi_node);
1532 : 29321130 : for (i = 0; i < n; i++)
1533 : : {
1534 : 19547420 : tree branch = PHI_ARG_DEF (loop_phi_node, i);
1535 : 19547420 : basic_block bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1536 : :
1537 : : /* When the branch is oriented to the loop's body, it does
1538 : : not contribute to the initial condition. */
1539 : 19547420 : if (flow_bb_inside_loop_p (loop, bb))
1540 : 9773710 : continue;
1541 : :
1542 : 9773710 : if (init_cond == chrec_not_analyzed_yet)
1543 : : {
1544 : 9773710 : init_cond = branch;
1545 : 9773710 : continue;
1546 : : }
1547 : :
1548 : 0 : if (TREE_CODE (branch) == SSA_NAME)
1549 : : {
1550 : 0 : init_cond = chrec_dont_know;
1551 : 0 : break;
1552 : : }
1553 : :
1554 : 0 : init_cond = chrec_merge (init_cond, branch);
1555 : : }
1556 : :
1557 : : /* Ooops -- a loop without an entry??? */
1558 : 9773710 : if (init_cond == chrec_not_analyzed_yet)
1559 : 0 : init_cond = chrec_dont_know;
1560 : :
1561 : : /* We may not have fully constant propagated IL. Handle degenerate PHIs here
1562 : : to not miss important early loop unrollings. */
1563 : 9773710 : init_cond = follow_copies_to_constant (init_cond);
1564 : :
1565 : 9773710 : if (dump_file && (dump_flags & TDF_SCEV))
1566 : : {
1567 : 2 : fprintf (dump_file, " (init_cond = ");
1568 : 2 : print_generic_expr (dump_file, init_cond);
1569 : 2 : fprintf (dump_file, "))\n");
1570 : : }
1571 : :
1572 : 9773710 : return init_cond;
1573 : : }
1574 : :
1575 : : /* Analyze the scalar evolution for LOOP_PHI_NODE. */
1576 : :
1577 : : static tree
1578 : 9773710 : interpret_loop_phi (class loop *loop, gphi *loop_phi_node)
1579 : : {
1580 : 9773710 : class loop *phi_loop = loop_containing_stmt (loop_phi_node);
1581 : 9773710 : tree init_cond;
1582 : :
1583 : 9773710 : gcc_assert (phi_loop == loop);
1584 : :
1585 : : /* Otherwise really interpret the loop phi. */
1586 : 9773710 : init_cond = analyze_initial_condition (loop_phi_node);
1587 : 9773710 : return analyze_evolution_in_loop (loop_phi_node, init_cond);
1588 : : }
1589 : :
1590 : : /* This function merges the branches of a condition-phi-node,
1591 : : contained in the outermost loop, and whose arguments are already
1592 : : analyzed. */
1593 : :
1594 : : static tree
1595 : 2401077 : interpret_condition_phi (class loop *loop, gphi *condition_phi)
1596 : : {
1597 : 2401077 : int i, n = gimple_phi_num_args (condition_phi);
1598 : 2401077 : tree res = chrec_not_analyzed_yet;
1599 : :
1600 : 5101107 : for (i = 0; i < n; i++)
1601 : : {
1602 : 4560919 : tree branch_chrec;
1603 : :
1604 : 4560919 : if (backedge_phi_arg_p (condition_phi, i))
1605 : : {
1606 : 41081 : res = chrec_dont_know;
1607 : 41081 : break;
1608 : : }
1609 : :
1610 : 4519838 : branch_chrec = analyze_scalar_evolution
1611 : 4519838 : (loop, PHI_ARG_DEF (condition_phi, i));
1612 : :
1613 : 4519838 : res = chrec_merge (res, branch_chrec);
1614 : 4519838 : if (res == chrec_dont_know)
1615 : : break;
1616 : : }
1617 : :
1618 : 2401077 : return res;
1619 : : }
1620 : :
1621 : : /* Interpret the operation RHS1 OP RHS2. If we didn't
1622 : : analyze this node before, follow the definitions until ending
1623 : : either on an analyzed GIMPLE_ASSIGN, or on a loop-phi-node. On the
1624 : : return path, this function propagates evolutions (ala constant copy
1625 : : propagation). OPND1 is not a GIMPLE expression because we could
1626 : : analyze the effect of an inner loop: see interpret_loop_phi. */
1627 : :
1628 : : static tree
1629 : 40732654 : interpret_rhs_expr (class loop *loop, gimple *at_stmt,
1630 : : tree type, tree rhs1, enum tree_code code, tree rhs2)
1631 : : {
1632 : 40732654 : tree res, chrec1, chrec2, ctype;
1633 : 40732654 : gimple *def;
1634 : :
1635 : 40732654 : if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
1636 : : {
1637 : 9675264 : if (is_gimple_min_invariant (rhs1))
1638 : 2248346 : return chrec_convert (type, rhs1, at_stmt);
1639 : :
1640 : 7426918 : if (code == SSA_NAME)
1641 : 120668 : return chrec_convert (type, analyze_scalar_evolution (loop, rhs1),
1642 : 120668 : at_stmt);
1643 : : }
1644 : :
1645 : 38363640 : switch (code)
1646 : : {
1647 : 291482 : case ADDR_EXPR:
1648 : 291482 : if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF
1649 : 291482 : || handled_component_p (TREE_OPERAND (rhs1, 0)))
1650 : : {
1651 : 291474 : machine_mode mode;
1652 : 291474 : poly_int64 bitsize, bitpos;
1653 : 291474 : int unsignedp, reversep;
1654 : 291474 : int volatilep = 0;
1655 : 291474 : tree base, offset;
1656 : 291474 : tree chrec3;
1657 : 291474 : tree unitpos;
1658 : :
1659 : 291474 : base = get_inner_reference (TREE_OPERAND (rhs1, 0),
1660 : : &bitsize, &bitpos, &offset, &mode,
1661 : : &unsignedp, &reversep, &volatilep);
1662 : :
1663 : 291474 : if (TREE_CODE (base) == MEM_REF)
1664 : : {
1665 : 215060 : rhs2 = TREE_OPERAND (base, 1);
1666 : 215060 : rhs1 = TREE_OPERAND (base, 0);
1667 : :
1668 : 215060 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1669 : 215060 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1670 : 215060 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1671 : 215060 : chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt);
1672 : 215060 : chrec1 = instantiate_parameters (loop, chrec1);
1673 : 215060 : chrec2 = instantiate_parameters (loop, chrec2);
1674 : 215060 : res = chrec_fold_plus (type, chrec1, chrec2);
1675 : : }
1676 : : else
1677 : : {
1678 : 76414 : chrec1 = analyze_scalar_evolution_for_address_of (loop, base);
1679 : 76414 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1680 : 76414 : res = chrec1;
1681 : : }
1682 : :
1683 : 291474 : if (offset != NULL_TREE)
1684 : : {
1685 : 141983 : chrec2 = analyze_scalar_evolution (loop, offset);
1686 : 141983 : chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt);
1687 : 141983 : chrec2 = instantiate_parameters (loop, chrec2);
1688 : 141983 : res = chrec_fold_plus (type, res, chrec2);
1689 : : }
1690 : :
1691 : 291474 : if (maybe_ne (bitpos, 0))
1692 : : {
1693 : 101584 : unitpos = size_int (exact_div (bitpos, BITS_PER_UNIT));
1694 : 101584 : chrec3 = analyze_scalar_evolution (loop, unitpos);
1695 : 101584 : chrec3 = chrec_convert (TREE_TYPE (unitpos), chrec3, at_stmt);
1696 : 101584 : chrec3 = instantiate_parameters (loop, chrec3);
1697 : 101584 : res = chrec_fold_plus (type, res, chrec3);
1698 : : }
1699 : : }
1700 : : else
1701 : 8 : res = chrec_dont_know;
1702 : : break;
1703 : :
1704 : 3119377 : case POINTER_PLUS_EXPR:
1705 : 3119377 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1706 : 3119377 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1707 : 3119377 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1708 : 3119377 : chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt);
1709 : 3119377 : chrec1 = instantiate_parameters (loop, chrec1);
1710 : 3119377 : chrec2 = instantiate_parameters (loop, chrec2);
1711 : 3119377 : res = chrec_fold_plus (type, chrec1, chrec2);
1712 : 3119377 : break;
1713 : :
1714 : 10800921 : case PLUS_EXPR:
1715 : 10800921 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1716 : 10800921 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1717 : 10800921 : ctype = type;
1718 : : /* When the stmt is conditionally executed re-write the CHREC
1719 : : into a form that has well-defined behavior on overflow. */
1720 : 10800921 : if (at_stmt
1721 : 9670563 : && INTEGRAL_TYPE_P (type)
1722 : 9569704 : && ! TYPE_OVERFLOW_WRAPS (type)
1723 : 18112404 : && ! dominated_by_p (CDI_DOMINATORS, loop->latch,
1724 : 7311483 : gimple_bb (at_stmt)))
1725 : 605791 : ctype = unsigned_type_for (type);
1726 : 10800921 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1727 : 10800921 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1728 : 10800921 : chrec1 = instantiate_parameters (loop, chrec1);
1729 : 10800921 : chrec2 = instantiate_parameters (loop, chrec2);
1730 : 10800921 : res = chrec_fold_plus (ctype, chrec1, chrec2);
1731 : 10800921 : if (type != ctype)
1732 : 605791 : res = chrec_convert (type, res, at_stmt);
1733 : : break;
1734 : :
1735 : 1310465 : case MINUS_EXPR:
1736 : 1310465 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1737 : 1310465 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1738 : 1310465 : ctype = type;
1739 : : /* When the stmt is conditionally executed re-write the CHREC
1740 : : into a form that has well-defined behavior on overflow. */
1741 : 1310465 : if (at_stmt
1742 : 1254620 : && INTEGRAL_TYPE_P (type)
1743 : 1217903 : && ! TYPE_OVERFLOW_WRAPS (type)
1744 : 1779102 : && ! dominated_by_p (CDI_DOMINATORS,
1745 : 468637 : loop->latch, gimple_bb (at_stmt)))
1746 : 83224 : ctype = unsigned_type_for (type);
1747 : 1310465 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1748 : 1310465 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1749 : 1310465 : chrec1 = instantiate_parameters (loop, chrec1);
1750 : 1310465 : chrec2 = instantiate_parameters (loop, chrec2);
1751 : 1310465 : res = chrec_fold_minus (ctype, chrec1, chrec2);
1752 : 1310465 : if (type != ctype)
1753 : 83224 : res = chrec_convert (type, res, at_stmt);
1754 : : break;
1755 : :
1756 : 75349 : case NEGATE_EXPR:
1757 : 75349 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1758 : 75349 : ctype = type;
1759 : : /* When the stmt is conditionally executed re-write the CHREC
1760 : : into a form that has well-defined behavior on overflow. */
1761 : 75349 : if (at_stmt
1762 : 65149 : && INTEGRAL_TYPE_P (type)
1763 : 63383 : && ! TYPE_OVERFLOW_WRAPS (type)
1764 : 111531 : && ! dominated_by_p (CDI_DOMINATORS,
1765 : 36182 : loop->latch, gimple_bb (at_stmt)))
1766 : 7747 : ctype = unsigned_type_for (type);
1767 : 75349 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1768 : : /* TYPE may be integer, real or complex, so use fold_convert. */
1769 : 75349 : chrec1 = instantiate_parameters (loop, chrec1);
1770 : 75349 : res = chrec_fold_multiply (ctype, chrec1,
1771 : : fold_convert (ctype, integer_minus_one_node));
1772 : 75349 : if (type != ctype)
1773 : 7747 : res = chrec_convert (type, res, at_stmt);
1774 : : break;
1775 : :
1776 : 27837 : case BIT_NOT_EXPR:
1777 : : /* Handle ~X as -1 - X. */
1778 : 27837 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1779 : 27837 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1780 : 27837 : chrec1 = instantiate_parameters (loop, chrec1);
1781 : 27837 : res = chrec_fold_minus (type,
1782 : : fold_convert (type, integer_minus_one_node),
1783 : : chrec1);
1784 : 27837 : break;
1785 : :
1786 : 5613024 : case MULT_EXPR:
1787 : 5613024 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1788 : 5613024 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1789 : 5613024 : ctype = type;
1790 : : /* When the stmt is conditionally executed re-write the CHREC
1791 : : into a form that has well-defined behavior on overflow. */
1792 : 5613024 : if (at_stmt
1793 : 3781540 : && INTEGRAL_TYPE_P (type)
1794 : 3664539 : && ! TYPE_OVERFLOW_WRAPS (type)
1795 : 7267817 : && ! dominated_by_p (CDI_DOMINATORS,
1796 : 1654793 : loop->latch, gimple_bb (at_stmt)))
1797 : 149153 : ctype = unsigned_type_for (type);
1798 : 5613024 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1799 : 5613024 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1800 : 5613024 : chrec1 = instantiate_parameters (loop, chrec1);
1801 : 5613024 : chrec2 = instantiate_parameters (loop, chrec2);
1802 : 5613024 : res = chrec_fold_multiply (ctype, chrec1, chrec2);
1803 : 5613024 : if (type != ctype)
1804 : 149153 : res = chrec_convert (type, res, at_stmt);
1805 : : break;
1806 : :
1807 : 165980 : case LSHIFT_EXPR:
1808 : 165980 : {
1809 : : /* Handle A<<B as A * (1<<B). */
1810 : 165980 : tree uns = unsigned_type_for (type);
1811 : 165980 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1812 : 165980 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1813 : 165980 : chrec1 = chrec_convert (uns, chrec1, at_stmt);
1814 : 165980 : chrec1 = instantiate_parameters (loop, chrec1);
1815 : 165980 : chrec2 = instantiate_parameters (loop, chrec2);
1816 : :
1817 : 165980 : tree one = build_int_cst (uns, 1);
1818 : 165980 : chrec2 = fold_build2 (LSHIFT_EXPR, uns, one, chrec2);
1819 : 165980 : res = chrec_fold_multiply (uns, chrec1, chrec2);
1820 : 165980 : res = chrec_convert (type, res, at_stmt);
1821 : : }
1822 : 165980 : break;
1823 : :
1824 : 7835166 : CASE_CONVERT:
1825 : : /* In case we have a truncation of a widened operation that in
1826 : : the truncated type has undefined overflow behavior analyze
1827 : : the operation done in an unsigned type of the same precision
1828 : : as the final truncation. We cannot derive a scalar evolution
1829 : : for the widened operation but for the truncated result. */
1830 : 7835166 : if (TREE_CODE (type) == INTEGER_TYPE
1831 : 7574466 : && TREE_CODE (TREE_TYPE (rhs1)) == INTEGER_TYPE
1832 : 7101881 : && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (rhs1))
1833 : 420978 : && TYPE_OVERFLOW_UNDEFINED (type)
1834 : 242640 : && TREE_CODE (rhs1) == SSA_NAME
1835 : 242482 : && (def = SSA_NAME_DEF_STMT (rhs1))
1836 : 242482 : && is_gimple_assign (def)
1837 : 153294 : && TREE_CODE_CLASS (gimple_assign_rhs_code (def)) == tcc_binary
1838 : 7945562 : && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST)
1839 : : {
1840 : 78374 : tree utype = unsigned_type_for (type);
1841 : 78374 : chrec1 = interpret_rhs_expr (loop, at_stmt, utype,
1842 : : gimple_assign_rhs1 (def),
1843 : : gimple_assign_rhs_code (def),
1844 : : gimple_assign_rhs2 (def));
1845 : : }
1846 : : else
1847 : 7756792 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1848 : 7835166 : res = chrec_convert (type, chrec1, at_stmt, true, rhs1);
1849 : 7835166 : break;
1850 : :
1851 : 364531 : case BIT_AND_EXPR:
1852 : : /* Given int variable A, handle A&0xffff as (int)(unsigned short)A.
1853 : : If A is SCEV and its value is in the range of representable set
1854 : : of type unsigned short, the result expression is a (no-overflow)
1855 : : SCEV. */
1856 : 364531 : res = chrec_dont_know;
1857 : 364531 : if (tree_fits_uhwi_p (rhs2))
1858 : : {
1859 : 243114 : int precision;
1860 : 243114 : unsigned HOST_WIDE_INT val = tree_to_uhwi (rhs2);
1861 : :
1862 : 243114 : val ++;
1863 : : /* Skip if value of rhs2 wraps in unsigned HOST_WIDE_INT or
1864 : : it's not the maximum value of a smaller type than rhs1. */
1865 : 243114 : if (val != 0
1866 : 185855 : && (precision = exact_log2 (val)) > 0
1867 : 428969 : && (unsigned) precision < TYPE_PRECISION (TREE_TYPE (rhs1)))
1868 : : {
1869 : 185855 : tree utype = build_nonstandard_integer_type (precision, 1);
1870 : :
1871 : 185855 : if (TYPE_PRECISION (utype) < TYPE_PRECISION (TREE_TYPE (rhs1)))
1872 : : {
1873 : 185855 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1874 : 185855 : chrec1 = chrec_convert (utype, chrec1, at_stmt);
1875 : 185855 : res = chrec_convert (TREE_TYPE (rhs1), chrec1, at_stmt);
1876 : : }
1877 : : }
1878 : : }
1879 : : break;
1880 : :
1881 : 8759508 : default:
1882 : 8759508 : res = chrec_dont_know;
1883 : 8759508 : break;
1884 : : }
1885 : :
1886 : : return res;
1887 : : }
1888 : :
1889 : : /* Interpret the expression EXPR. */
1890 : :
1891 : : static tree
1892 : 8426715 : interpret_expr (class loop *loop, gimple *at_stmt, tree expr)
1893 : : {
1894 : 8426715 : enum tree_code code;
1895 : 8426715 : tree type = TREE_TYPE (expr), op0, op1;
1896 : :
1897 : 8426715 : if (automatically_generated_chrec_p (expr))
1898 : : return expr;
1899 : :
1900 : 8421763 : if (TREE_CODE (expr) == POLYNOMIAL_CHREC
1901 : 8421337 : || TREE_CODE (expr) == CALL_EXPR
1902 : 16843053 : || get_gimple_rhs_class (TREE_CODE (expr)) == GIMPLE_TERNARY_RHS)
1903 : : return chrec_dont_know;
1904 : :
1905 : 8350725 : extract_ops_from_tree (expr, &code, &op0, &op1);
1906 : :
1907 : 8350725 : return interpret_rhs_expr (loop, at_stmt, type,
1908 : 8350725 : op0, code, op1);
1909 : : }
1910 : :
1911 : : /* Interpret the rhs of the assignment STMT. */
1912 : :
1913 : : static tree
1914 : 32303555 : interpret_gimple_assign (class loop *loop, gimple *stmt)
1915 : : {
1916 : 32303555 : tree type = TREE_TYPE (gimple_assign_lhs (stmt));
1917 : 32303555 : enum tree_code code = gimple_assign_rhs_code (stmt);
1918 : :
1919 : 32303555 : return interpret_rhs_expr (loop, stmt, type,
1920 : : gimple_assign_rhs1 (stmt), code,
1921 : 32303555 : gimple_assign_rhs2 (stmt));
1922 : : }
1923 : :
1924 : :
1925 : :
1926 : : /* This section contains all the entry points:
1927 : : - number_of_iterations_in_loop,
1928 : : - analyze_scalar_evolution,
1929 : : - instantiate_parameters.
1930 : : */
1931 : :
1932 : : /* Helper recursive function. */
1933 : :
1934 : : static tree
1935 : 67709343 : analyze_scalar_evolution_1 (class loop *loop, tree var)
1936 : : {
1937 : 67709343 : gimple *def;
1938 : 67709343 : basic_block bb;
1939 : 67709343 : class loop *def_loop;
1940 : 67709343 : tree res;
1941 : :
1942 : 67709343 : if (TREE_CODE (var) != SSA_NAME)
1943 : 8426715 : return interpret_expr (loop, NULL, var);
1944 : :
1945 : 59282628 : def = SSA_NAME_DEF_STMT (var);
1946 : 59282628 : bb = gimple_bb (def);
1947 : 59282628 : def_loop = bb->loop_father;
1948 : :
1949 : 59282628 : if (!flow_bb_inside_loop_p (loop, bb))
1950 : : {
1951 : : /* Keep symbolic form, but look through obvious copies for constants. */
1952 : 10560482 : res = follow_copies_to_constant (var);
1953 : 10560482 : goto set_and_end;
1954 : : }
1955 : :
1956 : 48722146 : if (loop != def_loop)
1957 : : {
1958 : 3712733 : res = analyze_scalar_evolution_1 (def_loop, var);
1959 : 3712733 : class loop *loop_to_skip = superloop_at_depth (def_loop,
1960 : 3712733 : loop_depth (loop) + 1);
1961 : 3712733 : res = compute_overall_effect_of_inner_loop (loop_to_skip, res);
1962 : 3712733 : if (chrec_contains_symbols_defined_in_loop (res, loop->num))
1963 : 276298 : res = analyze_scalar_evolution_1 (loop, res);
1964 : 3712733 : goto set_and_end;
1965 : : }
1966 : :
1967 : 45009413 : switch (gimple_code (def))
1968 : : {
1969 : 32303555 : case GIMPLE_ASSIGN:
1970 : 32303555 : res = interpret_gimple_assign (loop, def);
1971 : 32303555 : break;
1972 : :
1973 : 12174787 : case GIMPLE_PHI:
1974 : 24349574 : if (loop_phi_node_p (def))
1975 : 9773710 : res = interpret_loop_phi (loop, as_a <gphi *> (def));
1976 : : else
1977 : 2401077 : res = interpret_condition_phi (loop, as_a <gphi *> (def));
1978 : : break;
1979 : :
1980 : 531071 : default:
1981 : 531071 : res = chrec_dont_know;
1982 : 531071 : break;
1983 : : }
1984 : :
1985 : 59282628 : set_and_end:
1986 : :
1987 : : /* Keep the symbolic form. */
1988 : 59282628 : if (res == chrec_dont_know)
1989 : 21551120 : res = var;
1990 : :
1991 : 59282628 : if (loop == def_loop)
1992 : 45009413 : set_scalar_evolution (block_before_loop (loop), var, res);
1993 : :
1994 : : return res;
1995 : : }
1996 : :
1997 : : /* Analyzes and returns the scalar evolution of the ssa_name VAR in
1998 : : LOOP. LOOP is the loop in which the variable is used.
1999 : :
2000 : : Example of use: having a pointer VAR to a SSA_NAME node, STMT a
2001 : : pointer to the statement that uses this variable, in order to
2002 : : determine the evolution function of the variable, use the following
2003 : : calls:
2004 : :
2005 : : loop_p loop = loop_containing_stmt (stmt);
2006 : : tree chrec_with_symbols = analyze_scalar_evolution (loop, var);
2007 : : tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols);
2008 : : */
2009 : :
2010 : : tree
2011 : 175648792 : analyze_scalar_evolution (class loop *loop, tree var)
2012 : : {
2013 : 175648792 : tree res;
2014 : :
2015 : : /* ??? Fix callers. */
2016 : 175648792 : if (! loop)
2017 : : return var;
2018 : :
2019 : 175535621 : if (dump_file && (dump_flags & TDF_SCEV))
2020 : : {
2021 : 30 : fprintf (dump_file, "(analyze_scalar_evolution \n");
2022 : 30 : fprintf (dump_file, " (loop_nb = %d)\n", loop->num);
2023 : 30 : fprintf (dump_file, " (scalar = ");
2024 : 30 : print_generic_expr (dump_file, var);
2025 : 30 : fprintf (dump_file, ")\n");
2026 : : }
2027 : :
2028 : 175535621 : res = get_scalar_evolution (block_before_loop (loop), var);
2029 : 175535621 : if (res == chrec_not_analyzed_yet)
2030 : : {
2031 : : /* We'll recurse into instantiate_scev, avoid tearing down the
2032 : : instantiate cache repeatedly and keep it live from here. */
2033 : 63720312 : bool destr = false;
2034 : 63720312 : if (!global_cache)
2035 : : {
2036 : 38045162 : global_cache = new instantiate_cache_type;
2037 : 38045162 : destr = true;
2038 : : }
2039 : 63720312 : res = analyze_scalar_evolution_1 (loop, var);
2040 : 63720312 : if (destr)
2041 : : {
2042 : 38045162 : delete global_cache;
2043 : 38045162 : global_cache = NULL;
2044 : : }
2045 : : }
2046 : :
2047 : 175535621 : if (dump_file && (dump_flags & TDF_SCEV))
2048 : 30 : fprintf (dump_file, ")\n");
2049 : :
2050 : : return res;
2051 : : }
2052 : :
2053 : : /* If CHREC doesn't overflow, set the nonwrapping flag. */
2054 : :
2055 : 9768202 : void record_nonwrapping_chrec (tree chrec)
2056 : : {
2057 : 9768202 : CHREC_NOWRAP(chrec) = 1;
2058 : :
2059 : 9768202 : if (dump_file && (dump_flags & TDF_SCEV))
2060 : : {
2061 : 6 : fprintf (dump_file, "(record_nonwrapping_chrec: ");
2062 : 6 : print_generic_expr (dump_file, chrec);
2063 : 6 : fprintf (dump_file, ")\n");
2064 : : }
2065 : 9768202 : }
2066 : :
2067 : : /* Return true if CHREC's nonwrapping flag is set. */
2068 : :
2069 : 182739 : bool nonwrapping_chrec_p (tree chrec)
2070 : : {
2071 : 182739 : if (!chrec || TREE_CODE(chrec) != POLYNOMIAL_CHREC)
2072 : : return false;
2073 : :
2074 : 182739 : return CHREC_NOWRAP(chrec);
2075 : : }
2076 : :
2077 : : /* Analyzes and returns the scalar evolution of VAR address in LOOP. */
2078 : :
2079 : : static tree
2080 : 76414 : analyze_scalar_evolution_for_address_of (class loop *loop, tree var)
2081 : : {
2082 : 76414 : return analyze_scalar_evolution (loop, build_fold_addr_expr (var));
2083 : : }
2084 : :
2085 : : /* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to
2086 : : WRTO_LOOP (which should be a superloop of USE_LOOP)
2087 : :
2088 : : FOLDED_CASTS is set to true if resolve_mixers used
2089 : : chrec_convert_aggressive (TODO -- not really, we are way too conservative
2090 : : at the moment in order to keep things simple).
2091 : :
2092 : : To illustrate the meaning of USE_LOOP and WRTO_LOOP, consider the following
2093 : : example:
2094 : :
2095 : : for (i = 0; i < 100; i++) -- loop 1
2096 : : {
2097 : : for (j = 0; j < 100; j++) -- loop 2
2098 : : {
2099 : : k1 = i;
2100 : : k2 = j;
2101 : :
2102 : : use2 (k1, k2);
2103 : :
2104 : : for (t = 0; t < 100; t++) -- loop 3
2105 : : use3 (k1, k2);
2106 : :
2107 : : }
2108 : : use1 (k1, k2);
2109 : : }
2110 : :
2111 : : Both k1 and k2 are invariants in loop3, thus
2112 : : analyze_scalar_evolution_in_loop (loop3, loop3, k1) = k1
2113 : : analyze_scalar_evolution_in_loop (loop3, loop3, k2) = k2
2114 : :
2115 : : As they are invariant, it does not matter whether we consider their
2116 : : usage in loop 3 or loop 2, hence
2117 : : analyze_scalar_evolution_in_loop (loop2, loop3, k1) =
2118 : : analyze_scalar_evolution_in_loop (loop2, loop2, k1) = i
2119 : : analyze_scalar_evolution_in_loop (loop2, loop3, k2) =
2120 : : analyze_scalar_evolution_in_loop (loop2, loop2, k2) = [0,+,1]_2
2121 : :
2122 : : Similarly for their evolutions with respect to loop 1. The values of K2
2123 : : in the use in loop 2 vary independently on loop 1, thus we cannot express
2124 : : the evolution with respect to loop 1:
2125 : : analyze_scalar_evolution_in_loop (loop1, loop3, k1) =
2126 : : analyze_scalar_evolution_in_loop (loop1, loop2, k1) = [0,+,1]_1
2127 : : analyze_scalar_evolution_in_loop (loop1, loop3, k2) =
2128 : : analyze_scalar_evolution_in_loop (loop1, loop2, k2) = dont_know
2129 : :
2130 : : The value of k2 in the use in loop 1 is known, though:
2131 : : analyze_scalar_evolution_in_loop (loop1, loop1, k1) = [0,+,1]_1
2132 : : analyze_scalar_evolution_in_loop (loop1, loop1, k2) = 100
2133 : : */
2134 : :
2135 : : static tree
2136 : 45046884 : analyze_scalar_evolution_in_loop (class loop *wrto_loop, class loop *use_loop,
2137 : : tree version, bool *folded_casts)
2138 : : {
2139 : 45046884 : bool val = false;
2140 : 45046884 : tree ev = version, tmp;
2141 : :
2142 : : /* We cannot just do
2143 : :
2144 : : tmp = analyze_scalar_evolution (use_loop, version);
2145 : : ev = resolve_mixers (wrto_loop, tmp, folded_casts);
2146 : :
2147 : : as resolve_mixers would query the scalar evolution with respect to
2148 : : wrto_loop. For example, in the situation described in the function
2149 : : comment, suppose that wrto_loop = loop1, use_loop = loop3 and
2150 : : version = k2. Then
2151 : :
2152 : : analyze_scalar_evolution (use_loop, version) = k2
2153 : :
2154 : : and resolve_mixers (loop1, k2, folded_casts) finds that the value of
2155 : : k2 in loop 1 is 100, which is a wrong result, since we are interested
2156 : : in the value in loop 3.
2157 : :
2158 : : Instead, we need to proceed from use_loop to wrto_loop loop by loop,
2159 : : each time checking that there is no evolution in the inner loop. */
2160 : :
2161 : 45046884 : if (folded_casts)
2162 : 45046884 : *folded_casts = false;
2163 : 47244694 : while (1)
2164 : : {
2165 : 46145789 : tmp = analyze_scalar_evolution (use_loop, ev);
2166 : 46145789 : ev = resolve_mixers (use_loop, tmp, folded_casts);
2167 : :
2168 : 46145789 : if (use_loop == wrto_loop)
2169 : : return ev;
2170 : :
2171 : : /* If the value of the use changes in the inner loop, we cannot express
2172 : : its value in the outer loop (we might try to return interval chrec,
2173 : : but we do not have a user for it anyway) */
2174 : 4139776 : if (!no_evolution_in_loop_p (ev, use_loop->num, &val)
2175 : 4139776 : || !val)
2176 : 3040871 : return chrec_dont_know;
2177 : :
2178 : 1098905 : use_loop = loop_outer (use_loop);
2179 : : }
2180 : : }
2181 : :
2182 : :
2183 : : /* Computes a hash function for database element ELT. */
2184 : :
2185 : : static inline hashval_t
2186 : 289909 : hash_idx_scev_info (const void *elt_)
2187 : : {
2188 : 289909 : unsigned idx = ((size_t) elt_) - 2;
2189 : 289909 : return scev_info_hasher::hash (&global_cache->entries[idx]);
2190 : : }
2191 : :
2192 : : /* Compares database elements E1 and E2. */
2193 : :
2194 : : static inline int
2195 : 28308093 : eq_idx_scev_info (const void *e1, const void *e2)
2196 : : {
2197 : 28308093 : unsigned idx1 = ((size_t) e1) - 2;
2198 : 28308093 : return scev_info_hasher::equal (&global_cache->entries[idx1],
2199 : 28308093 : (const scev_info_str *) e2);
2200 : : }
2201 : :
2202 : : /* Returns from CACHE the slot number of the cached chrec for NAME. */
2203 : :
2204 : : static unsigned
2205 : 56660360 : get_instantiated_value_entry (instantiate_cache_type &cache,
2206 : : tree name, edge instantiate_below)
2207 : : {
2208 : 56660360 : if (!cache.map)
2209 : : {
2210 : 26159910 : cache.map = htab_create (10, hash_idx_scev_info, eq_idx_scev_info, NULL);
2211 : 26159910 : cache.entries.create (10);
2212 : : }
2213 : :
2214 : 56660360 : scev_info_str e;
2215 : 56660360 : e.name_version = SSA_NAME_VERSION (name);
2216 : 56660360 : e.instantiated_below = instantiate_below->dest->index;
2217 : 56660360 : void **slot = htab_find_slot_with_hash (cache.map, &e,
2218 : : scev_info_hasher::hash (&e), INSERT);
2219 : 56660360 : if (!*slot)
2220 : : {
2221 : 29385820 : e.chrec = chrec_not_analyzed_yet;
2222 : 29385820 : *slot = (void *)(size_t)(cache.entries.length () + 2);
2223 : 29385820 : cache.entries.safe_push (e);
2224 : : }
2225 : :
2226 : 56660360 : return ((size_t)*slot) - 2;
2227 : : }
2228 : :
2229 : :
2230 : : /* Return the closed_loop_phi node for VAR. If there is none, return
2231 : : NULL_TREE. */
2232 : :
2233 : : static tree
2234 : 1789566 : loop_closed_phi_def (tree var)
2235 : : {
2236 : 1789566 : class loop *loop;
2237 : 1789566 : edge exit;
2238 : 1789566 : gphi *phi;
2239 : 1789566 : gphi_iterator psi;
2240 : :
2241 : 1789566 : if (var == NULL_TREE
2242 : 1789566 : || TREE_CODE (var) != SSA_NAME)
2243 : : return NULL_TREE;
2244 : :
2245 : 1789566 : loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var));
2246 : 1789566 : exit = single_exit (loop);
2247 : 1789566 : if (!exit)
2248 : : return NULL_TREE;
2249 : :
2250 : 1446534 : for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi))
2251 : : {
2252 : 879547 : phi = psi.phi ();
2253 : 879547 : if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var)
2254 : 230943 : return PHI_RESULT (phi);
2255 : : }
2256 : :
2257 : : return NULL_TREE;
2258 : : }
2259 : :
2260 : : static tree instantiate_scev_r (edge, class loop *, class loop *,
2261 : : tree, bool *, int);
2262 : :
2263 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2264 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2265 : :
2266 : : CHREC is an SSA_NAME to be instantiated.
2267 : :
2268 : : CACHE is the cache of already instantiated values.
2269 : :
2270 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2271 : : conversions that may wrap in signed/pointer type are folded, as long
2272 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2273 : : then we don't do such fold.
2274 : :
2275 : : SIZE_EXPR is used for computing the size of the expression to be
2276 : : instantiated, and to stop if it exceeds some limit. */
2277 : :
2278 : : static tree
2279 : 100617433 : instantiate_scev_name (edge instantiate_below,
2280 : : class loop *evolution_loop, class loop *inner_loop,
2281 : : tree chrec,
2282 : : bool *fold_conversions,
2283 : : int size_expr)
2284 : : {
2285 : 100617433 : tree res;
2286 : 100617433 : class loop *def_loop;
2287 : 100617433 : basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (chrec));
2288 : :
2289 : : /* A parameter, nothing to do. */
2290 : 100617433 : if (!def_bb
2291 : 100617433 : || !dominated_by_p (CDI_DOMINATORS, def_bb, instantiate_below->dest))
2292 : 43957073 : return chrec;
2293 : :
2294 : : /* We cache the value of instantiated variable to avoid exponential
2295 : : time complexity due to reevaluations. We also store the convenient
2296 : : value in the cache in order to prevent infinite recursion -- we do
2297 : : not want to instantiate the SSA_NAME if it is in a mixer
2298 : : structure. This is used for avoiding the instantiation of
2299 : : recursively defined functions, such as:
2300 : :
2301 : : | a_2 -> {0, +, 1, +, a_2}_1 */
2302 : :
2303 : 56660360 : unsigned si = get_instantiated_value_entry (*global_cache,
2304 : : chrec, instantiate_below);
2305 : 56660360 : if (global_cache->get (si) != chrec_not_analyzed_yet)
2306 : : return global_cache->get (si);
2307 : :
2308 : : /* On recursion return chrec_dont_know. */
2309 : 29385820 : global_cache->set (si, chrec_dont_know);
2310 : :
2311 : 29385820 : def_loop = find_common_loop (evolution_loop, def_bb->loop_father);
2312 : :
2313 : 29385820 : if (! dominated_by_p (CDI_DOMINATORS,
2314 : 29385820 : def_loop->header, instantiate_below->dest))
2315 : : {
2316 : 179362 : gimple *def = SSA_NAME_DEF_STMT (chrec);
2317 : 179362 : if (gassign *ass = dyn_cast <gassign *> (def))
2318 : : {
2319 : 126644 : switch (gimple_assign_rhs_class (ass))
2320 : : {
2321 : 5224 : case GIMPLE_UNARY_RHS:
2322 : 5224 : {
2323 : 5224 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2324 : : inner_loop, gimple_assign_rhs1 (ass),
2325 : : fold_conversions, size_expr);
2326 : 5224 : if (op0 == chrec_dont_know)
2327 : : return chrec_dont_know;
2328 : 1233 : res = fold_build1 (gimple_assign_rhs_code (ass),
2329 : : TREE_TYPE (chrec), op0);
2330 : 1233 : break;
2331 : : }
2332 : 53613 : case GIMPLE_BINARY_RHS:
2333 : 53613 : {
2334 : 53613 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2335 : : inner_loop, gimple_assign_rhs1 (ass),
2336 : : fold_conversions, size_expr);
2337 : 53613 : if (op0 == chrec_dont_know)
2338 : : return chrec_dont_know;
2339 : 11698 : tree op1 = instantiate_scev_r (instantiate_below, evolution_loop,
2340 : : inner_loop, gimple_assign_rhs2 (ass),
2341 : : fold_conversions, size_expr);
2342 : 5849 : if (op1 == chrec_dont_know)
2343 : : return chrec_dont_know;
2344 : 2227 : res = fold_build2 (gimple_assign_rhs_code (ass),
2345 : : TREE_TYPE (chrec), op0, op1);
2346 : 2227 : break;
2347 : : }
2348 : 67807 : default:
2349 : 67807 : res = chrec_dont_know;
2350 : : }
2351 : : }
2352 : : else
2353 : 52718 : res = chrec_dont_know;
2354 : 123985 : global_cache->set (si, res);
2355 : 123985 : return res;
2356 : : }
2357 : :
2358 : : /* If the analysis yields a parametric chrec, instantiate the
2359 : : result again. */
2360 : 29206458 : res = analyze_scalar_evolution (def_loop, chrec);
2361 : :
2362 : : /* Don't instantiate default definitions. */
2363 : 29206458 : if (TREE_CODE (res) == SSA_NAME
2364 : 29206458 : && SSA_NAME_IS_DEFAULT_DEF (res))
2365 : : ;
2366 : :
2367 : : /* Don't instantiate loop-closed-ssa phi nodes. */
2368 : 29190554 : else if (TREE_CODE (res) == SSA_NAME
2369 : 86012279 : && loop_depth (loop_containing_stmt (SSA_NAME_DEF_STMT (res)))
2370 : 28411282 : > loop_depth (def_loop))
2371 : : {
2372 : 1808241 : if (res == chrec)
2373 : 1789566 : res = loop_closed_phi_def (chrec);
2374 : : else
2375 : : res = chrec;
2376 : :
2377 : : /* When there is no loop_closed_phi_def, it means that the
2378 : : variable is not used after the loop: try to still compute the
2379 : : value of the variable when exiting the loop. */
2380 : 1808241 : if (res == NULL_TREE)
2381 : : {
2382 : 1558623 : loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (chrec));
2383 : 1558623 : res = analyze_scalar_evolution (loop, chrec);
2384 : 1558623 : res = compute_overall_effect_of_inner_loop (loop, res);
2385 : 1558623 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2386 : : inner_loop, res,
2387 : : fold_conversions, size_expr);
2388 : : }
2389 : 249618 : else if (dominated_by_p (CDI_DOMINATORS,
2390 : 249618 : gimple_bb (SSA_NAME_DEF_STMT (res)),
2391 : 249618 : instantiate_below->dest))
2392 : 249618 : res = chrec_dont_know;
2393 : : }
2394 : :
2395 : 27382313 : else if (res != chrec_dont_know)
2396 : : {
2397 : 27382313 : if (inner_loop
2398 : 1146897 : && def_bb->loop_father != inner_loop
2399 : 27924214 : && !flow_loop_nested_p (def_bb->loop_father, inner_loop))
2400 : : /* ??? We could try to compute the overall effect of the loop here. */
2401 : 320 : res = chrec_dont_know;
2402 : : else
2403 : 27381993 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2404 : : inner_loop, res,
2405 : : fold_conversions, size_expr);
2406 : : }
2407 : :
2408 : : /* Store the correct value to the cache. */
2409 : 29206458 : global_cache->set (si, res);
2410 : 29206458 : return res;
2411 : : }
2412 : :
2413 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2414 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2415 : :
2416 : : CHREC is a polynomial chain of recurrence to be instantiated.
2417 : :
2418 : : CACHE is the cache of already instantiated values.
2419 : :
2420 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2421 : : conversions that may wrap in signed/pointer type are folded, as long
2422 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2423 : : then we don't do such fold.
2424 : :
2425 : : SIZE_EXPR is used for computing the size of the expression to be
2426 : : instantiated, and to stop if it exceeds some limit. */
2427 : :
2428 : : static tree
2429 : 55286662 : instantiate_scev_poly (edge instantiate_below,
2430 : : class loop *evolution_loop, class loop *,
2431 : : tree chrec, bool *fold_conversions, int size_expr)
2432 : : {
2433 : 55286662 : tree op1;
2434 : 110573324 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2435 : : get_chrec_loop (chrec),
2436 : 55286662 : CHREC_LEFT (chrec), fold_conversions,
2437 : : size_expr);
2438 : 55286662 : if (op0 == chrec_dont_know)
2439 : : return chrec_dont_know;
2440 : :
2441 : 110201122 : op1 = instantiate_scev_r (instantiate_below, evolution_loop,
2442 : : get_chrec_loop (chrec),
2443 : 55100561 : CHREC_RIGHT (chrec), fold_conversions,
2444 : : size_expr);
2445 : 55100561 : if (op1 == chrec_dont_know)
2446 : : return chrec_dont_know;
2447 : :
2448 : 54378944 : if (CHREC_LEFT (chrec) != op0
2449 : 54378944 : || CHREC_RIGHT (chrec) != op1)
2450 : : {
2451 : 7199715 : op1 = chrec_convert_rhs (chrec_type (op0), op1, NULL);
2452 : 7199715 : chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1);
2453 : : }
2454 : :
2455 : : return chrec;
2456 : : }
2457 : :
2458 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2459 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2460 : :
2461 : : "C0 CODE C1" is a binary expression of type TYPE to be instantiated.
2462 : :
2463 : : CACHE is the cache of already instantiated values.
2464 : :
2465 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2466 : : conversions that may wrap in signed/pointer type are folded, as long
2467 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2468 : : then we don't do such fold.
2469 : :
2470 : : SIZE_EXPR is used for computing the size of the expression to be
2471 : : instantiated, and to stop if it exceeds some limit. */
2472 : :
2473 : : static tree
2474 : 22991108 : instantiate_scev_binary (edge instantiate_below,
2475 : : class loop *evolution_loop, class loop *inner_loop,
2476 : : tree chrec, enum tree_code code,
2477 : : tree type, tree c0, tree c1,
2478 : : bool *fold_conversions, int size_expr)
2479 : : {
2480 : 22991108 : tree op1;
2481 : 22991108 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop,
2482 : : c0, fold_conversions, size_expr);
2483 : 22991108 : if (op0 == chrec_dont_know)
2484 : : return chrec_dont_know;
2485 : :
2486 : : /* While we eventually compute the same op1 if c0 == c1 the process
2487 : : of doing this is expensive so the following short-cut prevents
2488 : : exponential compile-time behavior. */
2489 : 22671412 : if (c0 != c1)
2490 : : {
2491 : 22650357 : op1 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop,
2492 : : c1, fold_conversions, size_expr);
2493 : 22650357 : if (op1 == chrec_dont_know)
2494 : : return chrec_dont_know;
2495 : : }
2496 : : else
2497 : : op1 = op0;
2498 : :
2499 : 22617718 : if (c0 != op0
2500 : 22617718 : || c1 != op1)
2501 : : {
2502 : 13391925 : op0 = chrec_convert (type, op0, NULL);
2503 : 13391925 : op1 = chrec_convert_rhs (type, op1, NULL);
2504 : :
2505 : 13391925 : switch (code)
2506 : : {
2507 : 7805108 : case POINTER_PLUS_EXPR:
2508 : 7805108 : case PLUS_EXPR:
2509 : 7805108 : return chrec_fold_plus (type, op0, op1);
2510 : :
2511 : 797469 : case MINUS_EXPR:
2512 : 797469 : return chrec_fold_minus (type, op0, op1);
2513 : :
2514 : 4789348 : case MULT_EXPR:
2515 : 4789348 : return chrec_fold_multiply (type, op0, op1);
2516 : :
2517 : 0 : default:
2518 : 0 : gcc_unreachable ();
2519 : : }
2520 : : }
2521 : :
2522 : 9225793 : return chrec ? chrec : fold_build2 (code, type, c0, c1);
2523 : : }
2524 : :
2525 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2526 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2527 : :
2528 : : "CHREC" that stands for a convert expression "(TYPE) OP" is to be
2529 : : instantiated.
2530 : :
2531 : : CACHE is the cache of already instantiated values.
2532 : :
2533 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2534 : : conversions that may wrap in signed/pointer type are folded, as long
2535 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2536 : : then we don't do such fold.
2537 : :
2538 : : SIZE_EXPR is used for computing the size of the expression to be
2539 : : instantiated, and to stop if it exceeds some limit. */
2540 : :
2541 : : static tree
2542 : 22338847 : instantiate_scev_convert (edge instantiate_below,
2543 : : class loop *evolution_loop, class loop *inner_loop,
2544 : : tree chrec, tree type, tree op,
2545 : : bool *fold_conversions, int size_expr)
2546 : : {
2547 : 22338847 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2548 : : inner_loop, op,
2549 : : fold_conversions, size_expr);
2550 : :
2551 : 22338847 : if (op0 == chrec_dont_know)
2552 : : return chrec_dont_know;
2553 : :
2554 : 18082068 : if (fold_conversions)
2555 : : {
2556 : 7227620 : tree tmp = chrec_convert_aggressive (type, op0, fold_conversions);
2557 : 7227620 : if (tmp)
2558 : : return tmp;
2559 : :
2560 : : /* If we used chrec_convert_aggressive, we can no longer assume that
2561 : : signed chrecs do not overflow, as chrec_convert does, so avoid
2562 : : calling it in that case. */
2563 : 6756150 : if (*fold_conversions)
2564 : : {
2565 : 6789 : if (chrec && op0 == op)
2566 : : return chrec;
2567 : :
2568 : 6789 : return fold_convert (type, op0);
2569 : : }
2570 : : }
2571 : :
2572 : 17603809 : return chrec_convert (type, op0, NULL);
2573 : : }
2574 : :
2575 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2576 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2577 : :
2578 : : CHREC is a BIT_NOT_EXPR or a NEGATE_EXPR expression to be instantiated.
2579 : : Handle ~X as -1 - X.
2580 : : Handle -X as -1 * X.
2581 : :
2582 : : CACHE is the cache of already instantiated values.
2583 : :
2584 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2585 : : conversions that may wrap in signed/pointer type are folded, as long
2586 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2587 : : then we don't do such fold.
2588 : :
2589 : : SIZE_EXPR is used for computing the size of the expression to be
2590 : : instantiated, and to stop if it exceeds some limit. */
2591 : :
2592 : : static tree
2593 : 314376 : instantiate_scev_not (edge instantiate_below,
2594 : : class loop *evolution_loop, class loop *inner_loop,
2595 : : tree chrec,
2596 : : enum tree_code code, tree type, tree op,
2597 : : bool *fold_conversions, int size_expr)
2598 : : {
2599 : 314376 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2600 : : inner_loop, op,
2601 : : fold_conversions, size_expr);
2602 : :
2603 : 314376 : if (op0 == chrec_dont_know)
2604 : : return chrec_dont_know;
2605 : :
2606 : 260819 : if (op != op0)
2607 : : {
2608 : 28943 : op0 = chrec_convert (type, op0, NULL);
2609 : :
2610 : 28943 : switch (code)
2611 : : {
2612 : 1761 : case BIT_NOT_EXPR:
2613 : 1761 : return chrec_fold_minus
2614 : 1761 : (type, fold_convert (type, integer_minus_one_node), op0);
2615 : :
2616 : 27182 : case NEGATE_EXPR:
2617 : 27182 : return chrec_fold_multiply
2618 : 27182 : (type, fold_convert (type, integer_minus_one_node), op0);
2619 : :
2620 : 0 : default:
2621 : 0 : gcc_unreachable ();
2622 : : }
2623 : : }
2624 : :
2625 : 231876 : return chrec ? chrec : fold_build1 (code, type, op0);
2626 : : }
2627 : :
2628 : : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2629 : : and EVOLUTION_LOOP, that were left under a symbolic form.
2630 : :
2631 : : CHREC is the scalar evolution to instantiate.
2632 : :
2633 : : CACHE is the cache of already instantiated values.
2634 : :
2635 : : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2636 : : conversions that may wrap in signed/pointer type are folded, as long
2637 : : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2638 : : then we don't do such fold.
2639 : :
2640 : : SIZE_EXPR is used for computing the size of the expression to be
2641 : : instantiated, and to stop if it exceeds some limit. */
2642 : :
2643 : : static tree
2644 : 333002900 : instantiate_scev_r (edge instantiate_below,
2645 : : class loop *evolution_loop, class loop *inner_loop,
2646 : : tree chrec,
2647 : : bool *fold_conversions, int size_expr)
2648 : : {
2649 : : /* Give up if the expression is larger than the MAX that we allow. */
2650 : 333002900 : if (size_expr++ > param_scev_max_expr_size)
2651 : 11 : return chrec_dont_know;
2652 : :
2653 : 333002889 : if (chrec == NULL_TREE
2654 : 461915480 : || automatically_generated_chrec_p (chrec)
2655 : 664094579 : || is_gimple_min_invariant (chrec))
2656 : 130823790 : return chrec;
2657 : :
2658 : 202179099 : switch (TREE_CODE (chrec))
2659 : : {
2660 : 100617433 : case SSA_NAME:
2661 : 100617433 : return instantiate_scev_name (instantiate_below, evolution_loop,
2662 : : inner_loop, chrec,
2663 : 100617433 : fold_conversions, size_expr);
2664 : :
2665 : 55286662 : case POLYNOMIAL_CHREC:
2666 : 55286662 : return instantiate_scev_poly (instantiate_below, evolution_loop,
2667 : : inner_loop, chrec,
2668 : 55286662 : fold_conversions, size_expr);
2669 : :
2670 : 22991108 : case POINTER_PLUS_EXPR:
2671 : 22991108 : case PLUS_EXPR:
2672 : 22991108 : case MINUS_EXPR:
2673 : 22991108 : case MULT_EXPR:
2674 : 22991108 : return instantiate_scev_binary (instantiate_below, evolution_loop,
2675 : : inner_loop, chrec,
2676 : : TREE_CODE (chrec), chrec_type (chrec),
2677 : 22991108 : TREE_OPERAND (chrec, 0),
2678 : 22991108 : TREE_OPERAND (chrec, 1),
2679 : 22991108 : fold_conversions, size_expr);
2680 : :
2681 : 22338847 : CASE_CONVERT:
2682 : 22338847 : return instantiate_scev_convert (instantiate_below, evolution_loop,
2683 : : inner_loop, chrec,
2684 : 22338847 : TREE_TYPE (chrec), TREE_OPERAND (chrec, 0),
2685 : 22338847 : fold_conversions, size_expr);
2686 : :
2687 : 314376 : case NEGATE_EXPR:
2688 : 314376 : case BIT_NOT_EXPR:
2689 : 314376 : return instantiate_scev_not (instantiate_below, evolution_loop,
2690 : : inner_loop, chrec,
2691 : 314376 : TREE_CODE (chrec), TREE_TYPE (chrec),
2692 : 314376 : TREE_OPERAND (chrec, 0),
2693 : 314376 : fold_conversions, size_expr);
2694 : :
2695 : 0 : case ADDR_EXPR:
2696 : 0 : if (is_gimple_min_invariant (chrec))
2697 : : return chrec;
2698 : : /* Fallthru. */
2699 : 0 : case SCEV_NOT_KNOWN:
2700 : 0 : return chrec_dont_know;
2701 : :
2702 : 0 : case SCEV_KNOWN:
2703 : 0 : return chrec_known;
2704 : :
2705 : 630673 : default:
2706 : 630673 : if (CONSTANT_CLASS_P (chrec))
2707 : : return chrec;
2708 : 630673 : return chrec_dont_know;
2709 : : }
2710 : : }
2711 : :
2712 : : /* Analyze all the parameters of the chrec that were left under a
2713 : : symbolic form. INSTANTIATE_BELOW is the basic block that stops the
2714 : : recursive instantiation of parameters: a parameter is a variable
2715 : : that is defined in a basic block that dominates INSTANTIATE_BELOW or
2716 : : a function parameter. */
2717 : :
2718 : : tree
2719 : 79169898 : instantiate_scev (edge instantiate_below, class loop *evolution_loop,
2720 : : tree chrec)
2721 : : {
2722 : 79169898 : tree res;
2723 : :
2724 : 79169898 : if (dump_file && (dump_flags & TDF_SCEV))
2725 : : {
2726 : 16 : fprintf (dump_file, "(instantiate_scev \n");
2727 : 16 : fprintf (dump_file, " (instantiate_below = %d -> %d)\n",
2728 : 16 : instantiate_below->src->index, instantiate_below->dest->index);
2729 : 16 : if (evolution_loop)
2730 : 16 : fprintf (dump_file, " (evolution_loop = %d)\n", evolution_loop->num);
2731 : 16 : fprintf (dump_file, " (chrec = ");
2732 : 16 : print_generic_expr (dump_file, chrec);
2733 : 16 : fprintf (dump_file, ")\n");
2734 : : }
2735 : :
2736 : 79169898 : bool destr = false;
2737 : 79169898 : if (!global_cache)
2738 : : {
2739 : 34169570 : global_cache = new instantiate_cache_type;
2740 : 34169570 : destr = true;
2741 : : }
2742 : :
2743 : 79169898 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2744 : : NULL, chrec, NULL, 0);
2745 : :
2746 : 79169898 : if (destr)
2747 : : {
2748 : 34169570 : delete global_cache;
2749 : 34169570 : global_cache = NULL;
2750 : : }
2751 : :
2752 : 79169898 : if (dump_file && (dump_flags & TDF_SCEV))
2753 : : {
2754 : 16 : fprintf (dump_file, " (res = ");
2755 : 16 : print_generic_expr (dump_file, res);
2756 : 16 : fprintf (dump_file, "))\n");
2757 : : }
2758 : :
2759 : 79169898 : return res;
2760 : : }
2761 : :
2762 : : /* Similar to instantiate_parameters, but does not introduce the
2763 : : evolutions in outer loops for LOOP invariants in CHREC, and does not
2764 : : care about causing overflows, as long as they do not affect value
2765 : : of an expression. */
2766 : :
2767 : : tree
2768 : 46145789 : resolve_mixers (class loop *loop, tree chrec, bool *folded_casts)
2769 : : {
2770 : 46145789 : bool destr = false;
2771 : 46145789 : bool fold_conversions = false;
2772 : 46145789 : if (!global_cache)
2773 : : {
2774 : 45486004 : global_cache = new instantiate_cache_type;
2775 : 45486004 : destr = true;
2776 : : }
2777 : :
2778 : 46145789 : tree ret = instantiate_scev_r (loop_preheader_edge (loop), loop, NULL,
2779 : : chrec, &fold_conversions, 0);
2780 : :
2781 : 46145789 : if (folded_casts && !*folded_casts)
2782 : 46145789 : *folded_casts = fold_conversions;
2783 : :
2784 : 46145789 : if (destr)
2785 : : {
2786 : 45486004 : delete global_cache;
2787 : 45486004 : global_cache = NULL;
2788 : : }
2789 : :
2790 : 46145789 : return ret;
2791 : : }
2792 : :
2793 : : /* Entry point for the analysis of the number of iterations pass.
2794 : : This function tries to safely approximate the number of iterations
2795 : : the loop will run. When this property is not decidable at compile
2796 : : time, the result is chrec_dont_know. Otherwise the result is a
2797 : : scalar or a symbolic parameter. When the number of iterations may
2798 : : be equal to zero and the property cannot be determined at compile
2799 : : time, the result is a COND_EXPR that represents in a symbolic form
2800 : : the conditions under which the number of iterations is not zero.
2801 : :
2802 : : Example of analysis: suppose that the loop has an exit condition:
2803 : :
2804 : : "if (b > 49) goto end_loop;"
2805 : :
2806 : : and that in a previous analysis we have determined that the
2807 : : variable 'b' has an evolution function:
2808 : :
2809 : : "EF = {23, +, 5}_2".
2810 : :
2811 : : When we evaluate the function at the point 5, i.e. the value of the
2812 : : variable 'b' after 5 iterations in the loop, we have EF (5) = 48,
2813 : : and EF (6) = 53. In this case the value of 'b' on exit is '53' and
2814 : : the loop body has been executed 6 times. */
2815 : :
2816 : : tree
2817 : 9548580 : number_of_latch_executions (class loop *loop)
2818 : : {
2819 : 9548580 : edge exit;
2820 : 9548580 : class tree_niter_desc niter_desc;
2821 : 9548580 : tree may_be_zero;
2822 : 9548580 : tree res;
2823 : :
2824 : : /* Determine whether the number of iterations in loop has already
2825 : : been computed. */
2826 : 9548580 : res = loop->nb_iterations;
2827 : 9548580 : if (res)
2828 : : return res;
2829 : :
2830 : 6283193 : may_be_zero = NULL_TREE;
2831 : :
2832 : 6283193 : if (dump_file && (dump_flags & TDF_SCEV))
2833 : 0 : fprintf (dump_file, "(number_of_iterations_in_loop = \n");
2834 : :
2835 : 6283193 : res = chrec_dont_know;
2836 : 6283193 : exit = single_exit (loop);
2837 : :
2838 : 6283193 : if (exit && number_of_iterations_exit (loop, exit, &niter_desc, false))
2839 : : {
2840 : 3151056 : may_be_zero = niter_desc.may_be_zero;
2841 : 3151056 : res = niter_desc.niter;
2842 : : }
2843 : :
2844 : 6283193 : if (res == chrec_dont_know
2845 : 3151056 : || !may_be_zero
2846 : 9434249 : || integer_zerop (may_be_zero))
2847 : : ;
2848 : 501538 : else if (integer_nonzerop (may_be_zero))
2849 : 27 : res = build_int_cst (TREE_TYPE (res), 0);
2850 : :
2851 : 501511 : else if (COMPARISON_CLASS_P (may_be_zero))
2852 : 501511 : res = fold_build3 (COND_EXPR, TREE_TYPE (res), may_be_zero,
2853 : : build_int_cst (TREE_TYPE (res), 0), res);
2854 : : else
2855 : 0 : res = chrec_dont_know;
2856 : :
2857 : 6283193 : if (dump_file && (dump_flags & TDF_SCEV))
2858 : : {
2859 : 0 : fprintf (dump_file, " (set_nb_iterations_in_loop = ");
2860 : 0 : print_generic_expr (dump_file, res);
2861 : 0 : fprintf (dump_file, "))\n");
2862 : : }
2863 : :
2864 : 6283193 : loop->nb_iterations = res;
2865 : 6283193 : return res;
2866 : 9548580 : }
2867 : :
2868 : :
2869 : : /* Counters for the stats. */
2870 : :
2871 : : struct chrec_stats
2872 : : {
2873 : : unsigned nb_chrecs;
2874 : : unsigned nb_affine;
2875 : : unsigned nb_affine_multivar;
2876 : : unsigned nb_higher_poly;
2877 : : unsigned nb_chrec_dont_know;
2878 : : unsigned nb_undetermined;
2879 : : };
2880 : :
2881 : : /* Reset the counters. */
2882 : :
2883 : : static inline void
2884 : 0 : reset_chrecs_counters (struct chrec_stats *stats)
2885 : : {
2886 : 0 : stats->nb_chrecs = 0;
2887 : 0 : stats->nb_affine = 0;
2888 : 0 : stats->nb_affine_multivar = 0;
2889 : 0 : stats->nb_higher_poly = 0;
2890 : 0 : stats->nb_chrec_dont_know = 0;
2891 : 0 : stats->nb_undetermined = 0;
2892 : : }
2893 : :
2894 : : /* Dump the contents of a CHREC_STATS structure. */
2895 : :
2896 : : static void
2897 : 0 : dump_chrecs_stats (FILE *file, struct chrec_stats *stats)
2898 : : {
2899 : 0 : fprintf (file, "\n(\n");
2900 : 0 : fprintf (file, "-----------------------------------------\n");
2901 : 0 : fprintf (file, "%d\taffine univariate chrecs\n", stats->nb_affine);
2902 : 0 : fprintf (file, "%d\taffine multivariate chrecs\n", stats->nb_affine_multivar);
2903 : 0 : fprintf (file, "%d\tdegree greater than 2 polynomials\n",
2904 : : stats->nb_higher_poly);
2905 : 0 : fprintf (file, "%d\tchrec_dont_know chrecs\n", stats->nb_chrec_dont_know);
2906 : 0 : fprintf (file, "-----------------------------------------\n");
2907 : 0 : fprintf (file, "%d\ttotal chrecs\n", stats->nb_chrecs);
2908 : 0 : fprintf (file, "%d\twith undetermined coefficients\n",
2909 : : stats->nb_undetermined);
2910 : 0 : fprintf (file, "-----------------------------------------\n");
2911 : 0 : fprintf (file, "%d\tchrecs in the scev database\n",
2912 : 0 : (int) scalar_evolution_info->elements ());
2913 : 0 : fprintf (file, "%d\tsets in the scev database\n", nb_set_scev);
2914 : 0 : fprintf (file, "%d\tgets in the scev database\n", nb_get_scev);
2915 : 0 : fprintf (file, "-----------------------------------------\n");
2916 : 0 : fprintf (file, ")\n\n");
2917 : 0 : }
2918 : :
2919 : : /* Gather statistics about CHREC. */
2920 : :
2921 : : static void
2922 : 0 : gather_chrec_stats (tree chrec, struct chrec_stats *stats)
2923 : : {
2924 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2925 : : {
2926 : 0 : fprintf (dump_file, "(classify_chrec ");
2927 : 0 : print_generic_expr (dump_file, chrec);
2928 : 0 : fprintf (dump_file, "\n");
2929 : : }
2930 : :
2931 : 0 : stats->nb_chrecs++;
2932 : :
2933 : 0 : if (chrec == NULL_TREE)
2934 : : {
2935 : 0 : stats->nb_undetermined++;
2936 : 0 : return;
2937 : : }
2938 : :
2939 : 0 : switch (TREE_CODE (chrec))
2940 : : {
2941 : 0 : case POLYNOMIAL_CHREC:
2942 : 0 : if (evolution_function_is_affine_p (chrec))
2943 : : {
2944 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2945 : 0 : fprintf (dump_file, " affine_univariate\n");
2946 : 0 : stats->nb_affine++;
2947 : : }
2948 : 0 : else if (evolution_function_is_affine_multivariate_p (chrec, 0))
2949 : : {
2950 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2951 : 0 : fprintf (dump_file, " affine_multivariate\n");
2952 : 0 : stats->nb_affine_multivar++;
2953 : : }
2954 : : else
2955 : : {
2956 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2957 : 0 : fprintf (dump_file, " higher_degree_polynomial\n");
2958 : 0 : stats->nb_higher_poly++;
2959 : : }
2960 : :
2961 : : break;
2962 : :
2963 : : default:
2964 : : break;
2965 : : }
2966 : :
2967 : 0 : if (chrec_contains_undetermined (chrec))
2968 : : {
2969 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2970 : 0 : fprintf (dump_file, " undetermined\n");
2971 : 0 : stats->nb_undetermined++;
2972 : : }
2973 : :
2974 : 0 : if (dump_file && (dump_flags & TDF_STATS))
2975 : 0 : fprintf (dump_file, ")\n");
2976 : : }
2977 : :
2978 : : /* Classify the chrecs of the whole database. */
2979 : :
2980 : : void
2981 : 0 : gather_stats_on_scev_database (void)
2982 : : {
2983 : 0 : struct chrec_stats stats;
2984 : :
2985 : 0 : if (!dump_file)
2986 : 0 : return;
2987 : :
2988 : 0 : reset_chrecs_counters (&stats);
2989 : :
2990 : 0 : hash_table<scev_info_hasher>::iterator iter;
2991 : 0 : scev_info_str *elt;
2992 : 0 : FOR_EACH_HASH_TABLE_ELEMENT (*scalar_evolution_info, elt, scev_info_str *,
2993 : : iter)
2994 : 0 : gather_chrec_stats (elt->chrec, &stats);
2995 : :
2996 : 0 : dump_chrecs_stats (dump_file, &stats);
2997 : : }
2998 : :
2999 : :
3000 : : /* Initialize the analysis of scalar evolutions for LOOPS. */
3001 : :
3002 : : void
3003 : 14087106 : scev_initialize (void)
3004 : : {
3005 : 14087106 : gcc_assert (! scev_initialized_p ()
3006 : : && loops_state_satisfies_p (cfun, LOOPS_NORMAL));
3007 : :
3008 : 14087106 : scalar_evolution_info = hash_table<scev_info_hasher>::create_ggc (100);
3009 : :
3010 : 50868345 : for (auto loop : loops_list (cfun, 0))
3011 : 8607027 : loop->nb_iterations = NULL_TREE;
3012 : 14087106 : }
3013 : :
3014 : : /* Return true if SCEV is initialized. */
3015 : :
3016 : : bool
3017 : 94436879 : scev_initialized_p (void)
3018 : : {
3019 : 94436879 : return scalar_evolution_info != NULL;
3020 : : }
3021 : :
3022 : : /* Cleans up the information cached by the scalar evolutions analysis
3023 : : in the hash table. */
3024 : :
3025 : : void
3026 : 22060808 : scev_reset_htab (void)
3027 : : {
3028 : 22060808 : if (!scalar_evolution_info)
3029 : : return;
3030 : :
3031 : 5639129 : scalar_evolution_info->empty ();
3032 : : }
3033 : :
3034 : : /* Cleans up the information cached by the scalar evolutions analysis
3035 : : in the hash table and in the loop->nb_iterations. */
3036 : :
3037 : : void
3038 : 12005938 : scev_reset (void)
3039 : : {
3040 : 12005938 : scev_reset_htab ();
3041 : :
3042 : 56354503 : for (auto loop : loops_list (cfun, 0))
3043 : 20336689 : loop->nb_iterations = NULL_TREE;
3044 : 12005938 : }
3045 : :
3046 : : /* Return true if the IV calculation in TYPE can overflow based on the knowledge
3047 : : of the upper bound on the number of iterations of LOOP, the BASE and STEP
3048 : : of IV.
3049 : :
3050 : : We do not use information whether TYPE can overflow so it is safe to
3051 : : use this test even for derived IVs not computed every iteration or
3052 : : hypotetical IVs to be inserted into code. */
3053 : :
3054 : : bool
3055 : 13928195 : iv_can_overflow_p (class loop *loop, tree type, tree base, tree step)
3056 : : {
3057 : 13928195 : widest_int nit;
3058 : 13928195 : wide_int base_min, base_max, step_min, step_max, type_min, type_max;
3059 : 13928195 : signop sgn = TYPE_SIGN (type);
3060 : 13928195 : int_range_max r;
3061 : :
3062 : 13928195 : if (integer_zerop (step))
3063 : : return false;
3064 : :
3065 : 27855740 : if (!INTEGRAL_TYPE_P (TREE_TYPE (base))
3066 : 25960746 : || !get_range_query (cfun)->range_of_expr (r, base)
3067 : 12980373 : || r.varying_p ()
3068 : 25644689 : || r.undefined_p ())
3069 : 2213992 : return true;
3070 : :
3071 : 11714199 : base_min = r.lower_bound ();
3072 : 11714199 : base_max = r.upper_bound ();
3073 : :
3074 : 23427823 : if (!INTEGRAL_TYPE_P (TREE_TYPE (step))
3075 : 23428398 : || !get_range_query (cfun)->range_of_expr (r, step)
3076 : 11714199 : || r.varying_p ()
3077 : 23346456 : || r.undefined_p ())
3078 : 81943 : return true;
3079 : :
3080 : 11632256 : step_min = r.lower_bound ();
3081 : 11632256 : step_max = r.upper_bound ();
3082 : :
3083 : 11632256 : if (!get_max_loop_iterations (loop, &nit))
3084 : : return true;
3085 : :
3086 : 10966931 : type_min = wi::min_value (type);
3087 : 10966931 : type_max = wi::max_value (type);
3088 : :
3089 : : /* Just sanity check that we don't see values out of the range of the type.
3090 : : In this case the arithmetics bellow would overflow. */
3091 : 10966931 : gcc_checking_assert (wi::ge_p (base_min, type_min, sgn)
3092 : : && wi::le_p (base_max, type_max, sgn));
3093 : :
3094 : : /* Account the possible increment in the last ieration. */
3095 : 10966931 : wi::overflow_type overflow = wi::OVF_NONE;
3096 : 10966931 : nit = wi::add (nit, 1, SIGNED, &overflow);
3097 : 10966931 : if (overflow)
3098 : : return true;
3099 : :
3100 : : /* NIT is typeless and can exceed the precision of the type. In this case
3101 : : overflow is always possible, because we know STEP is non-zero. */
3102 : 10966931 : if (wi::min_precision (nit, UNSIGNED) > TYPE_PRECISION (type))
3103 : : return true;
3104 : 10737811 : wide_int nit2 = wide_int::from (nit, TYPE_PRECISION (type), UNSIGNED);
3105 : :
3106 : : /* If step can be positive, check that nit*step <= type_max-base.
3107 : : This can be done by unsigned arithmetic and we only need to watch overflow
3108 : : in the multiplication. The right hand side can always be represented in
3109 : : the type. */
3110 : 10737811 : if (sgn == UNSIGNED || !wi::neg_p (step_max))
3111 : : {
3112 : 10694358 : wi::overflow_type overflow = wi::OVF_NONE;
3113 : 10694358 : if (wi::gtu_p (wi::mul (step_max, nit2, UNSIGNED, &overflow),
3114 : 21388716 : type_max - base_max)
3115 : 21388716 : || overflow)
3116 : 5418810 : return true;
3117 : : }
3118 : : /* If step can be negative, check that nit*(-step) <= base_min-type_min. */
3119 : 5319001 : if (sgn == SIGNED && wi::neg_p (step_min))
3120 : : {
3121 : 43728 : wi::overflow_type overflow, overflow2;
3122 : 43728 : overflow = overflow2 = wi::OVF_NONE;
3123 : 87456 : if (wi::gtu_p (wi::mul (wi::neg (step_min, &overflow2),
3124 : : nit2, UNSIGNED, &overflow),
3125 : 87456 : base_min - type_min)
3126 : 87456 : || overflow || overflow2)
3127 : 18568 : return true;
3128 : : }
3129 : :
3130 : : return false;
3131 : 13928195 : }
3132 : :
3133 : : /* Given EV with form of "(type) {inner_base, inner_step}_loop", this
3134 : : function tries to derive condition under which it can be simplified
3135 : : into "{(type)inner_base, (type)inner_step}_loop". The condition is
3136 : : the maximum number that inner iv can iterate. */
3137 : :
3138 : : static tree
3139 : 20365 : derive_simple_iv_with_niters (tree ev, tree *niters)
3140 : : {
3141 : 20365 : if (!CONVERT_EXPR_P (ev))
3142 : : return ev;
3143 : :
3144 : 20365 : tree inner_ev = TREE_OPERAND (ev, 0);
3145 : 20365 : if (TREE_CODE (inner_ev) != POLYNOMIAL_CHREC)
3146 : : return ev;
3147 : :
3148 : 20365 : tree init = CHREC_LEFT (inner_ev);
3149 : 20365 : tree step = CHREC_RIGHT (inner_ev);
3150 : 20365 : if (TREE_CODE (init) != INTEGER_CST
3151 : 20365 : || TREE_CODE (step) != INTEGER_CST || integer_zerop (step))
3152 : 7165 : return ev;
3153 : :
3154 : 13200 : tree type = TREE_TYPE (ev);
3155 : 13200 : tree inner_type = TREE_TYPE (inner_ev);
3156 : 13200 : if (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (type))
3157 : : return ev;
3158 : :
3159 : : /* Type conversion in "(type) {inner_base, inner_step}_loop" can be
3160 : : folded only if inner iv won't overflow. We compute the maximum
3161 : : number the inner iv can iterate before overflowing and return the
3162 : : simplified affine iv. */
3163 : 13200 : tree delta;
3164 : 13200 : init = fold_convert (type, init);
3165 : 13200 : step = fold_convert (type, step);
3166 : 13200 : ev = build_polynomial_chrec (CHREC_VARIABLE (inner_ev), init, step);
3167 : 13200 : if (tree_int_cst_sign_bit (step))
3168 : : {
3169 : 0 : tree bound = lower_bound_in_type (inner_type, inner_type);
3170 : 0 : delta = fold_build2 (MINUS_EXPR, type, init, fold_convert (type, bound));
3171 : 0 : step = fold_build1 (NEGATE_EXPR, type, step);
3172 : : }
3173 : : else
3174 : : {
3175 : 13200 : tree bound = upper_bound_in_type (inner_type, inner_type);
3176 : 13200 : delta = fold_build2 (MINUS_EXPR, type, fold_convert (type, bound), init);
3177 : : }
3178 : 13200 : *niters = fold_build2 (FLOOR_DIV_EXPR, type, delta, step);
3179 : 13200 : return ev;
3180 : : }
3181 : :
3182 : : /* Checks whether use of OP in USE_LOOP behaves as a simple affine iv with
3183 : : respect to WRTO_LOOP and returns its base and step in IV if possible
3184 : : (see analyze_scalar_evolution_in_loop for more details on USE_LOOP
3185 : : and WRTO_LOOP). If ALLOW_NONCONSTANT_STEP is true, we want step to be
3186 : : invariant in LOOP. Otherwise we require it to be an integer constant.
3187 : :
3188 : : IV->no_overflow is set to true if we are sure the iv cannot overflow (e.g.
3189 : : because it is computed in signed arithmetics). Consequently, adding an
3190 : : induction variable
3191 : :
3192 : : for (i = IV->base; ; i += IV->step)
3193 : :
3194 : : is only safe if IV->no_overflow is false, or TYPE_OVERFLOW_UNDEFINED is
3195 : : false for the type of the induction variable, or you can prove that i does
3196 : : not wrap by some other argument. Otherwise, this might introduce undefined
3197 : : behavior, and
3198 : :
3199 : : i = iv->base;
3200 : : for (; ; i = (type) ((unsigned type) i + (unsigned type) iv->step))
3201 : :
3202 : : must be used instead.
3203 : :
3204 : : When IV_NITERS is not NULL, this function also checks case in which OP
3205 : : is a conversion of an inner simple iv of below form:
3206 : :
3207 : : (outer_type){inner_base, inner_step}_loop.
3208 : :
3209 : : If type of inner iv has smaller precision than outer_type, it can't be
3210 : : folded into {(outer_type)inner_base, (outer_type)inner_step}_loop because
3211 : : the inner iv could overflow/wrap. In this case, we derive a condition
3212 : : under which the inner iv won't overflow/wrap and do the simplification.
3213 : : The derived condition normally is the maximum number the inner iv can
3214 : : iterate, and will be stored in IV_NITERS. This is useful in loop niter
3215 : : analysis, to derive break conditions when a loop must terminate, when is
3216 : : infinite. */
3217 : :
3218 : : bool
3219 : 46929240 : simple_iv_with_niters (class loop *wrto_loop, class loop *use_loop,
3220 : : tree op, affine_iv *iv, tree *iv_niters,
3221 : : bool allow_nonconstant_step)
3222 : : {
3223 : 46929240 : enum tree_code code;
3224 : 46929240 : tree type, ev, base, e;
3225 : 46929240 : wide_int extreme;
3226 : 46929240 : bool folded_casts;
3227 : :
3228 : 46929240 : iv->base = NULL_TREE;
3229 : 46929240 : iv->step = NULL_TREE;
3230 : 46929240 : iv->no_overflow = false;
3231 : :
3232 : 46929240 : type = TREE_TYPE (op);
3233 : 46929240 : if (!POINTER_TYPE_P (type)
3234 : 39000848 : && !INTEGRAL_TYPE_P (type))
3235 : : return false;
3236 : :
3237 : 44949525 : ev = analyze_scalar_evolution_in_loop (wrto_loop, use_loop, op,
3238 : : &folded_casts);
3239 : 44949525 : if (chrec_contains_undetermined (ev)
3240 : 44949525 : || chrec_contains_symbols_defined_in_loop (ev, wrto_loop->num))
3241 : 11775952 : return false;
3242 : :
3243 : 33173573 : if (tree_does_not_contain_chrecs (ev))
3244 : : {
3245 : 14626911 : iv->base = ev;
3246 : 14626911 : tree ev_type = TREE_TYPE (ev);
3247 : 14626911 : if (POINTER_TYPE_P (ev_type))
3248 : 2403859 : ev_type = sizetype;
3249 : :
3250 : 14626911 : iv->step = build_int_cst (ev_type, 0);
3251 : 14626911 : iv->no_overflow = true;
3252 : 14626911 : return true;
3253 : : }
3254 : :
3255 : : /* If we can derive valid scalar evolution with assumptions. */
3256 : 18546662 : if (iv_niters && TREE_CODE (ev) != POLYNOMIAL_CHREC)
3257 : 20365 : ev = derive_simple_iv_with_niters (ev, iv_niters);
3258 : :
3259 : 18546662 : if (TREE_CODE (ev) != POLYNOMIAL_CHREC)
3260 : : return false;
3261 : :
3262 : 18505534 : if (CHREC_VARIABLE (ev) != (unsigned) wrto_loop->num)
3263 : : return false;
3264 : :
3265 : 18505520 : iv->step = CHREC_RIGHT (ev);
3266 : 11707910 : if ((!allow_nonconstant_step && TREE_CODE (iv->step) != INTEGER_CST)
3267 : 29967509 : || tree_contains_chrecs (iv->step, NULL))
3268 : 257160 : return false;
3269 : :
3270 : 18248360 : iv->base = CHREC_LEFT (ev);
3271 : 18248360 : if (tree_contains_chrecs (iv->base, NULL))
3272 : : return false;
3273 : :
3274 : 18248360 : iv->no_overflow = !folded_casts && nowrap_type_p (type);
3275 : :
3276 : 18248360 : if (!iv->no_overflow
3277 : 18248360 : && !iv_can_overflow_p (wrto_loop, type, iv->base, iv->step))
3278 : 3545155 : iv->no_overflow = true;
3279 : :
3280 : : /* Try to simplify iv base:
3281 : :
3282 : : (signed T) ((unsigned T)base + step) ;; TREE_TYPE (base) == signed T
3283 : : == (signed T)(unsigned T)base + step
3284 : : == base + step
3285 : :
3286 : : If we can prove operation (base + step) doesn't overflow or underflow.
3287 : : Specifically, we try to prove below conditions are satisfied:
3288 : :
3289 : : base <= UPPER_BOUND (type) - step ;;step > 0
3290 : : base >= LOWER_BOUND (type) - step ;;step < 0
3291 : :
3292 : : This is done by proving the reverse conditions are false using loop's
3293 : : initial conditions.
3294 : :
3295 : : The is necessary to make loop niter, or iv overflow analysis easier
3296 : : for below example:
3297 : :
3298 : : int foo (int *a, signed char s, signed char l)
3299 : : {
3300 : : signed char i;
3301 : : for (i = s; i < l; i++)
3302 : : a[i] = 0;
3303 : : return 0;
3304 : : }
3305 : :
3306 : : Note variable I is firstly converted to type unsigned char, incremented,
3307 : : then converted back to type signed char. */
3308 : :
3309 : 18248360 : if (wrto_loop->num != use_loop->num)
3310 : : return true;
3311 : :
3312 : 18094407 : if (!CONVERT_EXPR_P (iv->base) || TREE_CODE (iv->step) != INTEGER_CST)
3313 : : return true;
3314 : :
3315 : 206204 : type = TREE_TYPE (iv->base);
3316 : 206204 : e = TREE_OPERAND (iv->base, 0);
3317 : 206204 : if (!tree_nop_conversion_p (type, TREE_TYPE (e))
3318 : 177746 : || TREE_CODE (e) != PLUS_EXPR
3319 : 98773 : || TREE_CODE (TREE_OPERAND (e, 1)) != INTEGER_CST
3320 : 278884 : || !tree_int_cst_equal (iv->step,
3321 : 72680 : fold_convert (type, TREE_OPERAND (e, 1))))
3322 : 150724 : return true;
3323 : 55480 : e = TREE_OPERAND (e, 0);
3324 : 55480 : if (!CONVERT_EXPR_P (e))
3325 : : return true;
3326 : 33564 : base = TREE_OPERAND (e, 0);
3327 : 33564 : if (!useless_type_conversion_p (type, TREE_TYPE (base)))
3328 : : return true;
3329 : :
3330 : 25164 : if (tree_int_cst_sign_bit (iv->step))
3331 : : {
3332 : 9147 : code = LT_EXPR;
3333 : 9147 : extreme = wi::min_value (type);
3334 : : }
3335 : : else
3336 : : {
3337 : 16017 : code = GT_EXPR;
3338 : 16017 : extreme = wi::max_value (type);
3339 : : }
3340 : 25164 : wi::overflow_type overflow = wi::OVF_NONE;
3341 : 25164 : extreme = wi::sub (extreme, wi::to_wide (iv->step),
3342 : 50328 : TYPE_SIGN (type), &overflow);
3343 : 25164 : if (overflow)
3344 : : return true;
3345 : 25140 : e = fold_build2 (code, boolean_type_node, base,
3346 : : wide_int_to_tree (type, extreme));
3347 : 25140 : e = simplify_using_initial_conditions (use_loop, e);
3348 : 25140 : if (!integer_zerop (e))
3349 : : return true;
3350 : :
3351 : 9820 : if (POINTER_TYPE_P (TREE_TYPE (base)))
3352 : : code = POINTER_PLUS_EXPR;
3353 : : else
3354 : : code = PLUS_EXPR;
3355 : :
3356 : 9820 : iv->base = fold_build2 (code, TREE_TYPE (base), base, iv->step);
3357 : 9820 : return true;
3358 : 46929240 : }
3359 : :
3360 : : /* Like simple_iv_with_niters, but return TRUE when OP behaves as a simple
3361 : : affine iv unconditionally. */
3362 : :
3363 : : bool
3364 : 19669528 : simple_iv (class loop *wrto_loop, class loop *use_loop, tree op,
3365 : : affine_iv *iv, bool allow_nonconstant_step)
3366 : : {
3367 : 19669528 : return simple_iv_with_niters (wrto_loop, use_loop, op, iv,
3368 : 19669528 : NULL, allow_nonconstant_step);
3369 : : }
3370 : :
3371 : : /* Finalize the scalar evolution analysis. */
3372 : :
3373 : : void
3374 : 14087106 : scev_finalize (void)
3375 : : {
3376 : 14087106 : if (!scalar_evolution_info)
3377 : : return;
3378 : 14087106 : scalar_evolution_info->empty ();
3379 : 14087106 : scalar_evolution_info = NULL;
3380 : 14087106 : free_numbers_of_iterations_estimates (cfun);
3381 : : }
3382 : :
3383 : : /* Returns true if the expression EXPR is considered to be too expensive
3384 : : for scev_const_prop. Sets *COND_OVERFLOW_P to true when the
3385 : : expression might contain a sub-expression that is subject to undefined
3386 : : overflow behavior and conditionally evaluated. */
3387 : :
3388 : : static bool
3389 : 9736307 : expression_expensive_p (tree expr, bool *cond_overflow_p,
3390 : : hash_map<tree, uint64_t> &cache, uint64_t &cost)
3391 : : {
3392 : 9736307 : enum tree_code code;
3393 : :
3394 : 9736307 : if (is_gimple_val (expr))
3395 : : return false;
3396 : :
3397 : 4084349 : code = TREE_CODE (expr);
3398 : 4084349 : if (code == TRUNC_DIV_EXPR
3399 : : || code == CEIL_DIV_EXPR
3400 : : || code == FLOOR_DIV_EXPR
3401 : : || code == ROUND_DIV_EXPR
3402 : : || code == TRUNC_MOD_EXPR
3403 : : || code == CEIL_MOD_EXPR
3404 : : || code == FLOOR_MOD_EXPR
3405 : 4084349 : || code == ROUND_MOD_EXPR
3406 : 4084349 : || code == EXACT_DIV_EXPR)
3407 : : {
3408 : : /* Division by power of two is usually cheap, so we allow it.
3409 : : Forbid anything else. */
3410 : 49110 : if (!integer_pow2p (TREE_OPERAND (expr, 1)))
3411 : : return true;
3412 : : }
3413 : :
3414 : 4074628 : bool visited_p;
3415 : 4074628 : uint64_t &local_cost = cache.get_or_insert (expr, &visited_p);
3416 : 4074628 : if (visited_p)
3417 : : {
3418 : 270 : uint64_t tem = cost + local_cost;
3419 : 270 : if (tem < cost)
3420 : : return true;
3421 : 270 : cost = tem;
3422 : 270 : return false;
3423 : : }
3424 : 4074358 : local_cost = 1;
3425 : :
3426 : 4074358 : uint64_t op_cost = 0;
3427 : 4074358 : if (code == CALL_EXPR)
3428 : : {
3429 : 102 : tree arg;
3430 : 102 : call_expr_arg_iterator iter;
3431 : : /* Even though is_inexpensive_builtin might say true, we will get a
3432 : : library call for popcount when backend does not have an instruction
3433 : : to do so. We consider this to be expensive and generate
3434 : : __builtin_popcount only when backend defines it. */
3435 : 102 : optab optab;
3436 : 102 : combined_fn cfn = get_call_combined_fn (expr);
3437 : 102 : switch (cfn)
3438 : : {
3439 : 31 : CASE_CFN_POPCOUNT:
3440 : 31 : optab = popcount_optab;
3441 : 31 : goto bitcount_call;
3442 : 58 : CASE_CFN_CLZ:
3443 : 58 : optab = clz_optab;
3444 : 58 : goto bitcount_call;
3445 : : CASE_CFN_CTZ:
3446 : : optab = ctz_optab;
3447 : 102 : bitcount_call:
3448 : : /* Check if opcode for popcount is available in the mode required. */
3449 : 102 : if (optab_handler (optab,
3450 : 102 : TYPE_MODE (TREE_TYPE (CALL_EXPR_ARG (expr, 0))))
3451 : : == CODE_FOR_nothing)
3452 : : {
3453 : 27 : machine_mode mode;
3454 : 27 : mode = TYPE_MODE (TREE_TYPE (CALL_EXPR_ARG (expr, 0)));
3455 : 27 : scalar_int_mode int_mode;
3456 : :
3457 : : /* If the mode is of 2 * UNITS_PER_WORD size, we can handle
3458 : : double-word popcount by emitting two single-word popcount
3459 : : instructions. */
3460 : 27 : if (is_a <scalar_int_mode> (mode, &int_mode)
3461 : 29 : && GET_MODE_SIZE (int_mode) == 2 * UNITS_PER_WORD
3462 : 2 : && (optab_handler (optab, word_mode)
3463 : : != CODE_FOR_nothing))
3464 : : break;
3465 : : /* If popcount is available for a wider mode, we emulate the
3466 : : operation for a narrow mode by first zero-extending the value
3467 : : and then computing popcount in the wider mode. Analogue for
3468 : : ctz. For clz we do the same except that we additionally have
3469 : : to subtract the difference of the mode precisions from the
3470 : : result. */
3471 : 25 : if (is_a <scalar_int_mode> (mode, &int_mode))
3472 : : {
3473 : 25 : machine_mode wider_mode_iter;
3474 : 124 : FOR_EACH_WIDER_MODE (wider_mode_iter, mode)
3475 : 99 : if (optab_handler (optab, wider_mode_iter)
3476 : : != CODE_FOR_nothing)
3477 : 0 : goto check_call_args;
3478 : : /* Operation ctz may be emulated via clz in expand_ctz. */
3479 : 25 : if (optab == ctz_optab)
3480 : : {
3481 : 0 : FOR_EACH_WIDER_MODE_FROM (wider_mode_iter, mode)
3482 : 0 : if (optab_handler (clz_optab, wider_mode_iter)
3483 : : != CODE_FOR_nothing)
3484 : 0 : goto check_call_args;
3485 : : }
3486 : : }
3487 : 25 : return true;
3488 : : }
3489 : : break;
3490 : :
3491 : 0 : default:
3492 : 0 : if (cfn == CFN_LAST
3493 : 0 : || !is_inexpensive_builtin (get_callee_fndecl (expr)))
3494 : 0 : return true;
3495 : : break;
3496 : : }
3497 : :
3498 : 77 : check_call_args:
3499 : 231 : FOR_EACH_CALL_EXPR_ARG (arg, iter, expr)
3500 : 77 : if (expression_expensive_p (arg, cond_overflow_p, cache, op_cost))
3501 : : return true;
3502 : 77 : *cache.get (expr) += op_cost;
3503 : 77 : cost += op_cost + 1;
3504 : 77 : return false;
3505 : : }
3506 : :
3507 : 4074256 : if (code == COND_EXPR)
3508 : : {
3509 : 1677 : if (expression_expensive_p (TREE_OPERAND (expr, 0), cond_overflow_p,
3510 : : cache, op_cost)
3511 : 1677 : || (EXPR_P (TREE_OPERAND (expr, 1))
3512 : 1675 : && EXPR_P (TREE_OPERAND (expr, 2)))
3513 : : /* If either branch has side effects or could trap. */
3514 : 1675 : || TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3515 : 1675 : || generic_expr_could_trap_p (TREE_OPERAND (expr, 1))
3516 : 1674 : || TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0))
3517 : 1674 : || generic_expr_could_trap_p (TREE_OPERAND (expr, 0))
3518 : 1674 : || expression_expensive_p (TREE_OPERAND (expr, 1), cond_overflow_p,
3519 : : cache, op_cost)
3520 : 3254 : || expression_expensive_p (TREE_OPERAND (expr, 2), cond_overflow_p,
3521 : : cache, op_cost))
3522 : 100 : return true;
3523 : : /* Conservatively assume there's overflow for now. */
3524 : 1577 : *cond_overflow_p = true;
3525 : 1577 : *cache.get (expr) += op_cost;
3526 : 1577 : cost += op_cost + 1;
3527 : 1577 : return false;
3528 : : }
3529 : :
3530 : 4072579 : switch (TREE_CODE_CLASS (code))
3531 : : {
3532 : 2119823 : case tcc_binary:
3533 : 2119823 : case tcc_comparison:
3534 : 2119823 : if (expression_expensive_p (TREE_OPERAND (expr, 1), cond_overflow_p,
3535 : : cache, op_cost))
3536 : : return true;
3537 : :
3538 : : /* Fallthru. */
3539 : 4069904 : case tcc_unary:
3540 : 4069904 : if (expression_expensive_p (TREE_OPERAND (expr, 0), cond_overflow_p,
3541 : : cache, op_cost))
3542 : : return true;
3543 : 4046207 : *cache.get (expr) += op_cost;
3544 : 4046207 : cost += op_cost + 1;
3545 : 4046207 : return false;
3546 : :
3547 : : default:
3548 : : return true;
3549 : : }
3550 : : }
3551 : :
3552 : : bool
3553 : 3541575 : expression_expensive_p (tree expr, bool *cond_overflow_p)
3554 : : {
3555 : 3541575 : hash_map<tree, uint64_t> cache;
3556 : 3541575 : uint64_t expanded_size = 0;
3557 : 3541575 : *cond_overflow_p = false;
3558 : 3541575 : return (expression_expensive_p (expr, cond_overflow_p, cache, expanded_size)
3559 : : /* ??? Both the explicit unsharing and gimplification of expr will
3560 : : expand shared trees to multiple copies.
3561 : : Guard against exponential growth by counting the visits and
3562 : : comparing againt the number of original nodes. Allow a tiny
3563 : : bit of duplication to catch some additional optimizations. */
3564 : 3551413 : || expanded_size > (cache.elements () + 1));
3565 : 3541575 : }
3566 : :
3567 : : /* Match.pd function to match bitwise inductive expression.
3568 : : .i.e.
3569 : : _2 = 1 << _1;
3570 : : _3 = ~_2;
3571 : : tmp_9 = _3 & tmp_12; */
3572 : : extern bool gimple_bitwise_induction_p (tree, tree *, tree (*)(tree));
3573 : :
3574 : : /* Return the inductive expression of bitwise operation if possible,
3575 : : otherwise returns DEF. */
3576 : : static tree
3577 : 17393 : analyze_and_compute_bitwise_induction_effect (class loop* loop,
3578 : : tree phidef,
3579 : : unsigned HOST_WIDE_INT niter)
3580 : : {
3581 : 17393 : tree match_op[3],inv, bitwise_scev;
3582 : 17393 : tree type = TREE_TYPE (phidef);
3583 : 17393 : gphi* header_phi = NULL;
3584 : :
3585 : : /* Match things like op2(MATCH_OP[2]), op1(MATCH_OP[1]), phidef(PHIDEF)
3586 : :
3587 : : op2 = PHI <phidef, inv>
3588 : : _1 = (int) bit_17;
3589 : : _3 = 1 << _1;
3590 : : op1 = ~_3;
3591 : : phidef = op1 & op2; */
3592 : 17393 : if (!gimple_bitwise_induction_p (phidef, &match_op[0], NULL)
3593 : 96 : || TREE_CODE (match_op[2]) != SSA_NAME
3594 : 17393 : || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[2])))
3595 : 96 : || gimple_bb (header_phi) != loop->header
3596 : 17487 : || gimple_phi_num_args (header_phi) != 2)
3597 : : return NULL_TREE;
3598 : :
3599 : 94 : if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop)) != phidef)
3600 : : return NULL_TREE;
3601 : :
3602 : 94 : bitwise_scev = analyze_scalar_evolution (loop, match_op[1]);
3603 : 94 : bitwise_scev = instantiate_parameters (loop, bitwise_scev);
3604 : :
3605 : : /* Make sure bits is in range of type precision. */
3606 : 94 : if (TREE_CODE (bitwise_scev) != POLYNOMIAL_CHREC
3607 : 94 : || !INTEGRAL_TYPE_P (TREE_TYPE (bitwise_scev))
3608 : 94 : || !tree_fits_uhwi_p (CHREC_LEFT (bitwise_scev))
3609 : 94 : || tree_to_uhwi (CHREC_LEFT (bitwise_scev)) >= TYPE_PRECISION (type)
3610 : 188 : || !tree_fits_shwi_p (CHREC_RIGHT (bitwise_scev)))
3611 : : return NULL_TREE;
3612 : :
3613 : 94 : enum bit_op_kind
3614 : : {
3615 : : INDUCTION_BIT_CLEAR,
3616 : : INDUCTION_BIT_IOR,
3617 : : INDUCTION_BIT_XOR,
3618 : : INDUCTION_BIT_RESET,
3619 : : INDUCTION_ZERO,
3620 : : INDUCTION_ALL
3621 : : };
3622 : :
3623 : 94 : enum bit_op_kind induction_kind;
3624 : 94 : enum tree_code code1
3625 : 94 : = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (phidef));
3626 : 94 : enum tree_code code2
3627 : 94 : = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (match_op[0]));
3628 : :
3629 : : /* BIT_CLEAR: A &= ~(1 << bit)
3630 : : BIT_RESET: A ^= (1 << bit).
3631 : : BIT_IOR: A |= (1 << bit)
3632 : : BIT_ZERO: A &= (1 << bit)
3633 : : BIT_ALL: A |= ~(1 << bit)
3634 : : BIT_XOR: A ^= ~(1 << bit).
3635 : : bit is induction variable. */
3636 : 94 : switch (code1)
3637 : : {
3638 : 24 : case BIT_AND_EXPR:
3639 : 36 : induction_kind = code2 == BIT_NOT_EXPR
3640 : 24 : ? INDUCTION_BIT_CLEAR
3641 : : : INDUCTION_ZERO;
3642 : 12 : break;
3643 : 46 : case BIT_IOR_EXPR:
3644 : 46 : induction_kind = code2 == BIT_NOT_EXPR
3645 : 46 : ? INDUCTION_ALL
3646 : : : INDUCTION_BIT_IOR;
3647 : : break;
3648 : 12 : case BIT_XOR_EXPR:
3649 : 12 : induction_kind = code2 == BIT_NOT_EXPR
3650 : 12 : ? INDUCTION_BIT_XOR
3651 : : : INDUCTION_BIT_RESET;
3652 : : break;
3653 : : /* A ^ ~(1 << bit) is equal to ~(A ^ (1 << bit)). */
3654 : 12 : case BIT_NOT_EXPR:
3655 : 12 : gcc_assert (code2 == BIT_XOR_EXPR);
3656 : : induction_kind = INDUCTION_BIT_XOR;
3657 : : break;
3658 : 0 : default:
3659 : 0 : gcc_unreachable ();
3660 : : }
3661 : :
3662 : 12 : if (induction_kind == INDUCTION_ZERO)
3663 : 12 : return build_zero_cst (type);
3664 : 82 : if (induction_kind == INDUCTION_ALL)
3665 : 12 : return build_all_ones_cst (type);
3666 : :
3667 : 140 : wide_int bits = wi::zero (TYPE_PRECISION (type));
3668 : 70 : HOST_WIDE_INT bit_start = tree_to_shwi (CHREC_LEFT (bitwise_scev));
3669 : 70 : HOST_WIDE_INT step = tree_to_shwi (CHREC_RIGHT (bitwise_scev));
3670 : 70 : HOST_WIDE_INT bit_final = bit_start + step * niter;
3671 : :
3672 : : /* bit_start, bit_final in range of [0,TYPE_PRECISION)
3673 : : implies all bits are set in range. */
3674 : 70 : if (bit_final >= TYPE_PRECISION (type)
3675 : 70 : || bit_final < 0)
3676 : : return NULL_TREE;
3677 : :
3678 : : /* Loop tripcount should be niter + 1. */
3679 : 1230 : for (unsigned i = 0; i != niter + 1; i++)
3680 : : {
3681 : 1160 : bits = wi::set_bit (bits, bit_start);
3682 : 1160 : bit_start += step;
3683 : : }
3684 : :
3685 : 70 : bool inverted = false;
3686 : 70 : switch (induction_kind)
3687 : : {
3688 : : case INDUCTION_BIT_CLEAR:
3689 : : code1 = BIT_AND_EXPR;
3690 : : inverted = true;
3691 : : break;
3692 : : case INDUCTION_BIT_IOR:
3693 : 70 : code1 = BIT_IOR_EXPR;
3694 : : break;
3695 : : case INDUCTION_BIT_RESET:
3696 : : code1 = BIT_XOR_EXPR;
3697 : : break;
3698 : : /* A ^= ~(1 << bit) is special, when loop tripcount is even,
3699 : : it's equal to A ^= bits, else A ^= ~bits. */
3700 : 12 : case INDUCTION_BIT_XOR:
3701 : 12 : code1 = BIT_XOR_EXPR;
3702 : 12 : if (niter % 2 == 0)
3703 : : inverted = true;
3704 : : break;
3705 : : default:
3706 : : gcc_unreachable ();
3707 : : }
3708 : :
3709 : : if (inverted)
3710 : 16 : bits = wi::bit_not (bits);
3711 : :
3712 : 70 : inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge (loop));
3713 : 70 : return fold_build2 (code1, type, inv, wide_int_to_tree (type, bits));
3714 : : }
3715 : :
3716 : : /* Match.pd function to match bitop with invariant expression
3717 : : .i.e.
3718 : : tmp_7 = _0 & _1; */
3719 : : extern bool gimple_bitop_with_inv_p (tree, tree *, tree (*)(tree));
3720 : :
3721 : : /* Return the inductive expression of bitop with invariant if possible,
3722 : : otherwise returns DEF. */
3723 : : static tree
3724 : 67818 : analyze_and_compute_bitop_with_inv_effect (class loop* loop, tree phidef,
3725 : : tree niter)
3726 : : {
3727 : 67818 : tree match_op[2],inv;
3728 : 67818 : tree type = TREE_TYPE (phidef);
3729 : 67818 : gphi* header_phi = NULL;
3730 : 67818 : enum tree_code code;
3731 : : /* match thing like op0 (match[0]), op1 (match[1]), phidef (PHIDEF)
3732 : :
3733 : : op1 = PHI <phidef, inv>
3734 : : phidef = op0 & op1
3735 : : if op0 is an invariant, it could change to
3736 : : phidef = op0 & inv. */
3737 : 67818 : gimple *def;
3738 : 67818 : def = SSA_NAME_DEF_STMT (phidef);
3739 : 67818 : if (!(is_gimple_assign (def)
3740 : 26092 : && ((code = gimple_assign_rhs_code (def)), true)
3741 : 26092 : && (code == BIT_AND_EXPR || code == BIT_IOR_EXPR
3742 : 20639 : || code == BIT_XOR_EXPR)))
3743 : : return NULL_TREE;
3744 : :
3745 : 6079 : match_op[0] = gimple_assign_rhs1 (def);
3746 : 6079 : match_op[1] = gimple_assign_rhs2 (def);
3747 : :
3748 : 6079 : if (expr_invariant_in_loop_p (loop, match_op[1]))
3749 : 203 : std::swap (match_op[0], match_op[1]);
3750 : :
3751 : 6079 : if (TREE_CODE (match_op[1]) != SSA_NAME
3752 : 6079 : || !expr_invariant_in_loop_p (loop, match_op[0])
3753 : 280 : || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[1])))
3754 : 197 : || gimple_bb (header_phi) != loop->header
3755 : 6261 : || gimple_phi_num_args (header_phi) != 2)
3756 : 5897 : return NULL_TREE;
3757 : :
3758 : 182 : if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop)) != phidef)
3759 : : return NULL_TREE;
3760 : :
3761 : 177 : enum tree_code code1
3762 : 177 : = gimple_assign_rhs_code (def);
3763 : :
3764 : 177 : if (code1 == BIT_XOR_EXPR)
3765 : : {
3766 : 42 : if (!tree_fits_uhwi_p (niter))
3767 : : return NULL_TREE;
3768 : 19 : unsigned HOST_WIDE_INT niter_num;
3769 : 19 : niter_num = tree_to_uhwi (niter);
3770 : 19 : if (niter_num % 2 != 0)
3771 : 10 : match_op[0] = build_zero_cst (type);
3772 : : }
3773 : :
3774 : 154 : inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge (loop));
3775 : 154 : return fold_build2 (code1, type, inv, match_op[0]);
3776 : : }
3777 : :
3778 : : /* Do final value replacement for LOOP, return true if we did anything. */
3779 : :
3780 : : bool
3781 : 630906 : final_value_replacement_loop (class loop *loop)
3782 : : {
3783 : : /* If we do not know exact number of iterations of the loop, we cannot
3784 : : replace the final value. */
3785 : 630906 : edge exit = single_exit (loop);
3786 : 630906 : if (!exit)
3787 : : return false;
3788 : :
3789 : 420599 : tree niter = number_of_latch_executions (loop);
3790 : 420599 : if (niter == chrec_dont_know)
3791 : : return false;
3792 : :
3793 : : /* Ensure that it is possible to insert new statements somewhere. */
3794 : 311813 : if (!single_pred_p (exit->dest))
3795 : 34958 : split_loop_exit_edge (exit);
3796 : :
3797 : : /* Set stmt insertion pointer. All stmts are inserted before this point. */
3798 : :
3799 : 311813 : class loop *ex_loop
3800 : 623626 : = superloop_at_depth (loop,
3801 : 381289 : loop_depth (exit->dest->loop_father) + 1);
3802 : :
3803 : 311813 : bool any = false;
3804 : 311813 : gphi_iterator psi;
3805 : 698611 : for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); )
3806 : : {
3807 : 386798 : gphi *phi = psi.phi ();
3808 : 386798 : tree rslt = PHI_RESULT (phi);
3809 : 386798 : tree phidef = PHI_ARG_DEF_FROM_EDGE (phi, exit);
3810 : 386798 : tree def = phidef;
3811 : 773031 : if (virtual_operand_p (def))
3812 : : {
3813 : 215665 : gsi_next (&psi);
3814 : 574331 : continue;
3815 : : }
3816 : :
3817 : 327231 : if (!POINTER_TYPE_P (TREE_TYPE (def))
3818 : 327145 : && !INTEGRAL_TYPE_P (TREE_TYPE (def)))
3819 : : {
3820 : 73774 : gsi_next (&psi);
3821 : 73774 : continue;
3822 : : }
3823 : :
3824 : 97359 : bool folded_casts;
3825 : 97359 : def = analyze_scalar_evolution_in_loop (ex_loop, loop, def,
3826 : : &folded_casts);
3827 : :
3828 : 97359 : tree bitinv_def, bit_def;
3829 : 97359 : unsigned HOST_WIDE_INT niter_num;
3830 : :
3831 : 97359 : if (def != chrec_dont_know)
3832 : 29541 : def = compute_overall_effect_of_inner_loop (ex_loop, def);
3833 : :
3834 : : /* Handle bitop with invariant induction expression.
3835 : :
3836 : : .i.e
3837 : : for (int i =0 ;i < 32; i++)
3838 : : tmp &= bit2;
3839 : : if bit2 is an invariant in loop which could simple to
3840 : : tmp &= bit2. */
3841 : 135636 : else if ((bitinv_def
3842 : 67818 : = analyze_and_compute_bitop_with_inv_effect (loop,
3843 : : phidef, niter)))
3844 : : def = bitinv_def;
3845 : :
3846 : : /* Handle bitwise induction expression.
3847 : :
3848 : : .i.e.
3849 : : for (int i = 0; i != 64; i+=3)
3850 : : res &= ~(1UL << i);
3851 : :
3852 : : RES can't be analyzed out by SCEV because it is not polynomially
3853 : : expressible, but in fact final value of RES can be replaced by
3854 : : RES & CONSTANT where CONSTANT all ones with bit {0,3,6,9,... ,63}
3855 : : being cleared, similar for BIT_IOR_EXPR/BIT_XOR_EXPR. */
3856 : 67664 : else if (tree_fits_uhwi_p (niter)
3857 : 27545 : && (niter_num = tree_to_uhwi (niter)) != 0
3858 : 27532 : && niter_num < TYPE_PRECISION (TREE_TYPE (phidef))
3859 : 67664 : && (bit_def
3860 : 17393 : = analyze_and_compute_bitwise_induction_effect (loop,
3861 : : phidef,
3862 : : niter_num)))
3863 : : def = bit_def;
3864 : :
3865 : 97359 : bool cond_overflow_p;
3866 : 97359 : if (!tree_does_not_contain_chrecs (def)
3867 : 29205 : || chrec_contains_symbols_defined_in_loop (def, ex_loop->num)
3868 : : /* Moving the computation from the loop may prolong life range
3869 : : of some ssa names, which may cause problems if they appear
3870 : : on abnormal edges. */
3871 : 29205 : || contains_abnormal_ssa_name_p (def)
3872 : : /* Do not emit expensive expressions. The rationale is that
3873 : : when someone writes a code like
3874 : :
3875 : : while (n > 45) n -= 45;
3876 : :
3877 : : he probably knows that n is not large, and does not want it
3878 : : to be turned into n %= 45. */
3879 : 126564 : || expression_expensive_p (def, &cond_overflow_p))
3880 : : {
3881 : 69227 : if (dump_file && (dump_flags & TDF_DETAILS))
3882 : : {
3883 : 56 : fprintf (dump_file, "not replacing:\n ");
3884 : 56 : print_gimple_stmt (dump_file, phi, 0);
3885 : 56 : fprintf (dump_file, "\n");
3886 : : }
3887 : 69227 : gsi_next (&psi);
3888 : 69227 : continue;
3889 : : }
3890 : :
3891 : : /* Eliminate the PHI node and replace it by a computation outside
3892 : : the loop. */
3893 : 28132 : if (dump_file)
3894 : : {
3895 : 127 : fprintf (dump_file, "\nfinal value replacement:\n ");
3896 : 127 : print_gimple_stmt (dump_file, phi, 0);
3897 : 127 : fprintf (dump_file, " with expr: ");
3898 : 127 : print_generic_expr (dump_file, def);
3899 : 127 : fprintf (dump_file, "\n");
3900 : : }
3901 : 28132 : any = true;
3902 : : /* ??? Here we'd like to have a unshare_expr that would assign
3903 : : shared sub-trees to new temporary variables either gimplified
3904 : : to a GIMPLE sequence or to a statement list (keeping this a
3905 : : GENERIC interface). */
3906 : 28132 : def = unshare_expr (def);
3907 : 28132 : auto loc = gimple_phi_arg_location (phi, exit->dest_idx);
3908 : 28132 : remove_phi_node (&psi, false);
3909 : :
3910 : : /* Propagate constants immediately, but leave an unused initialization
3911 : : around to avoid invalidating the SCEV cache. */
3912 : 34133 : if (CONSTANT_CLASS_P (def) && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rslt))
3913 : 6000 : replace_uses_by (rslt, def);
3914 : :
3915 : : /* Create the replacement statements. */
3916 : 28132 : gimple_seq stmts;
3917 : 28132 : def = force_gimple_operand (def, &stmts, false, NULL_TREE);
3918 : 28132 : gassign *ass = gimple_build_assign (rslt, def);
3919 : 28132 : gimple_set_location (ass, loc);
3920 : 28132 : gimple_seq_add_stmt (&stmts, ass);
3921 : :
3922 : : /* If def's type has undefined overflow and there were folded
3923 : : casts, rewrite all stmts added for def into arithmetics
3924 : : with defined overflow behavior. */
3925 : 28132 : if ((folded_casts
3926 : 382 : && ANY_INTEGRAL_TYPE_P (TREE_TYPE (def))
3927 : 644 : && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (def)))
3928 : 28514 : || cond_overflow_p)
3929 : : {
3930 : 1810 : gimple_stmt_iterator gsi2;
3931 : 1810 : gsi2 = gsi_start (stmts);
3932 : 21592 : while (!gsi_end_p (gsi2))
3933 : : {
3934 : 19782 : gimple *stmt = gsi_stmt (gsi2);
3935 : 19782 : if (is_gimple_assign (stmt)
3936 : 39550 : && arith_code_with_undefined_signed_overflow
3937 : 19768 : (gimple_assign_rhs_code (stmt)))
3938 : 5581 : rewrite_to_defined_overflow (&gsi2);
3939 : 19782 : gsi_next (&gsi2);
3940 : : }
3941 : : }
3942 : 28132 : gimple_stmt_iterator gsi = gsi_after_labels (exit->dest);
3943 : 28132 : gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
3944 : 28132 : if (dump_file)
3945 : : {
3946 : 127 : fprintf (dump_file, " final stmt:\n ");
3947 : 127 : print_gimple_stmt (dump_file, SSA_NAME_DEF_STMT (rslt), 0);
3948 : 127 : fprintf (dump_file, "\n");
3949 : : }
3950 : : }
3951 : :
3952 : : return any;
3953 : : }
3954 : :
3955 : : #include "gt-tree-scalar-evolution.h"
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